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On Thu, 20 Jan 2005 20:01:02 -0500, Jeff Morris
wrote: Sailors in 1975 were much better navigators than today. ======================================== That's probably a true statement as far as it goes. We had to be "better" navigators in terms of skill breadth and techniques. It was a matter of survival. To some that was all part of the challenge and fun, to others it was just something that had to be done so that you got where you were going. Reality is however, that many of those skills are doomed to obsolesence except among those who keep them alive as a hobby, just like knowing how to shoe your own horse or brew your own beer. Is that a bad thing? Perhaps, but there is a good side also. It is REALLY nice to know where you are at all times, and if practiced prudently, is a lot safer also. Sailing in the 70s was not always experienced navigators skillfully finding their way no matter what. I still remember calls to the Coast Guard from those lost in the fog asking for a RDF bearing to their boat. The USCG actually offered that service in the early 70s believe it or not, and could sometimes provide an approximate two bearing fix. The one thing they would not do was provide directions for obvious liability reasons. They would come out and try to find you however if it looked like you were in danger as a result of being lost, and it was not uncommon. Every person I know from that era, regardless of skills, quickly jumped on the latest technology breakthrough as soon as it became available at a reasonable price. |
On Fri, 21 Jan 2005 08:15:10 -0800, "Jim Donohue"
wrote: Go slow when in doubt. ========================== Good advice. Less damage to the rock, less damage to the boat. |
On Fri, 21 Jan 2005 11:45:30 -0500, Jeff Morris
wrote: Without the basic skills, you're in deep **** when the GPS fails. ================================ No argument with the need for basic skills but there's no excuse for GPS failure with hand held units selling for around $100. I was on a Bermuda race in 1996 where we lost every electronic device on board except my hand held GPS. |
Wayne.B wrote:
On Fri, 21 Jan 2005 11:45:30 -0500, Jeff Morris wrote: Without the basic skills, you're in deep **** when the GPS fails. ================================ No argument with the need for basic skills but there's no excuse for GPS failure with hand held units selling for around $100. I was on a Bermuda race in 1996 where we lost every electronic device on board except my hand held GPS. I've heard this often said, and in fact I keep an eTrex just inside the companionway. However, things tend to go wrong at the least convenient time. If the spiffy chartplotter goes south while your negotiating a tight channel, its little consolation that a cheap handheld is available. It may need batteries; it will probably take a few minutes to power up; its only giving Lat/Lon which is of little value unless the chart is handy; it won't have the current waypoint; etc., etc. A hundred miles offshore, this is not a problem, but we've specifically been talking about coastal cruising - the OP lives in Maine. The last day I cruised Maine I was leaving Casco Bay in peasoup, and I had my eTrex at hand with fresh batteries, just in case. |
Wayne.B wrote:
On Thu, 20 Jan 2005 20:01:02 -0500, Jeff Morris wrote: Sailors in 1975 were much better navigators than today. ======================================== That's probably a true statement as far as it goes. We had to be "better" navigators in terms of skill breadth and techniques. It was a matter of survival. To some that was all part of the challenge and fun, to others it was just something that had to be done so that you got where you were going. Reality is however, that many of those skills are doomed to obsolesence except among those who keep them alive as a hobby, just like knowing how to shoe your own horse or brew your own beer. Is that a bad thing? Perhaps, but there is a good side also. It is REALLY nice to know where you are at all times, and if practiced prudently, is a lot safer also. Sailing in the 70s was not always experienced navigators skillfully finding their way no matter what. I still remember calls to the Coast Guard from those lost in the fog asking for a RDF bearing to their boat. The USCG actually offered that service in the early 70s believe it or not, and could sometimes provide an approximate two bearing fix. The one thing they would not do was provide directions for obvious liability reasons. They would come out and try to find you however if it looked like you were in danger as a result of being lost, and it was not uncommon. Every person I know from that era, regardless of skills, quickly jumped on the latest technology breakthrough as soon as it became available at a reasonable price. You're bringing back memories with this. But who could afford a radio in the early 70s? I thought I was well equipped with a spinner and a Ray Jeff RDF. I think I finally got VHF (with 6 crystals) around 1980. |
In article et,
otnmbrd wrote: Jim Donohue wrote: Why with professional luddites like you and your ilk I am required for progress otn. As stated, "you just don't get it". In truth, I'm a prolific user of GPS, both the basic readout and connected to a chart plotter, making use of all the information it supplies. However, especially in the coastal waters I mainly traverse nowadays, it's NEVER my sole source of position information and in fact, plotting a GPS position isn't all that much quicker or necessarily as accurate as a simple radar range and bearing, or eyeball fix. The aside points out that the real amateur sailor with sufficient skill to cross oceans uses GPS otn...and have a likely non working celestial capability. It is in no way an excuse of any type...merely an observation on how life actually is. You likely don't like it otn but you really don't get a vote. You use your survey as an EXCUSE for not learning or using celestial. G By "non working" I assume you mean they have the ability but don't use it. That's their choice, just like it's the choice of many ship Masters making ocean crossings to require their people to occasionally take celestial fixes and when in sight of land or radar range, to take visual fixes as well as radar fixes and compare them to the GPS. I also note that in another reply, you are still not comfortable using radar for navigation.... that's too bad.... you're missing out on a great tool. otn I would like to add a simple note here. OTN talks about using Radar and the Mark One Eyeball to get position fixes while navigating in coastal and inshore waters. Ok, that is common practice, and has been for MANY years. Now consider the accuracy of those fixes, as compared with the accuracy of an Electronic Position Fixing Device. Mark One Eyeball.... Taking a sight with binocs even over a compass card will usually get a line within a degree or two, IF the guy is really good at it or is using one of those old WWII TBT's... Ok, now figure that your going to have to do that on at least two bearings, and better yet, three or four. Ok, now you have to go plot those bearings on the chart using the reverse bearing from the marker you sited on, and then figuring in the time difference between the bearings, and the speed of advance, of the vessel, and you don't get a REAL FIX, but an AREA of FIX that IS "Orders of Magnitude" bigger than the REALTIME GPS Fix. Radar..... Same thing here, except that your bearing will tend to be better, depending on the Horozontal Beamwidth of the antenna, and the distance, and area of the target which the bearing is to. Again, the AREA of the FIX will be smaller for the radar because the time to get the bearins, (two or more) will be shorter, but the plotting times and the speed of advance will be the same. Again the Area of fix will be "Orders of Magnitude" larger than the REALTIME GPS Fix. GPS Fix..... even with out WAAS, this should be in the 30 foot centered circle, and the speed of advance isn't even a problem due to the small amount of advance in the one second cycle times of GPS Calulations. The same can be said for LORAN-C with modern day Receivers, that have builtin Lat/LONG Calculators, especially if the route has been run before, and Know Anomalies in the TD's are already accounted for. Now all the above really is mostly not a GIANT Issue at 7 - 12 Knots, as there is always enough time to figure this all out. However, I defy anyone to show me how anything but a Very GOOD GPS Based Navigation System can be used on a Fast Ferry doing 35+ Knots inside Boston Harbour. Speed KILLS, and the faster these guys go, the faster one of them is going to run the rest of us over, because the navigator isn't watching where he is going, because he is busy PLOTTING his position. Explain to me why this isn't a problem...... Bruce in alaska -- add a 2 before @ |
On Fri, 21 Jan 2005 13:50:35 -0500, Jeff Morris
wrote: You're bringing back memories with this. But who could afford a radio in the early 70s? I thought I was well equipped with a spinner and a Ray Jeff RDF. I think I finally got VHF (with 6 crystals) around 1980. ======================================== I had the same setup in the 70s. Still have the RayJeff RDF out in the garage but think I chucked the VHF w/crystals when I cleaned out up north and moved to Florida. I had 2 receive crystals installed in the RDF for 2182 and 2670. Boats would call USCG on 2182 for a direction check and then get switched to 2670 while they homed in on them. It was pretty humorous listening at times. The REALLY well equipped boats in the 70s had a double sideband MF marine radio and an aircraft type VOR unit for direction finding. It was a big pricing breakthrough when Motorola came out with a frequency synthesized VHF for around $300. That unit sold with one of my old sailboats. |
On Fri, 21 Jan 2005 13:45:49 -0500, Jeff Morris
wrote: The last day I cruised Maine I was leaving Casco Bay in peasoup, and I had my eTrex at hand with fresh batteries, just in case. ========================================= Good idea but I'd also recommend loading some key waypoints into it in advance. It only takes a few minutes and can save a lot of fumbling around if you need it. |
"Jeff Morris" wrote in message ... Jim Donohue wrote: In many places you use the numbers from last time. Many of the numbers are published in guides or privately. Local knowledge is handy. You can also set up the course to minimize exposure. You mean, like plotting a course using piloting techniques? I mean like plotting the GPS waypoints on the chart. For a difficult segment of a voyage I would certainly plot the course even if the primary navigation is a chart plotter. I would have the waypoints in a secondary GPS. In general the errors are area wide. You work out the correction from known objects. You use radar and the bottom to assure yourself you did it correctly. You mean, like using piloting techniques? You cerrtainly back up your GPS course by what you have available particularly when the charts or waypoints are suspect. Go slow when in doubt. Why would you have any doubt? Don't you have absolute faith in your GPS? I have far more faith in a GPS, particularly a redundant pair, than I do in a LOP from a physical target. I have complete faith in nothing. The use of a GPS still involves risk...little things like entering a waypoint wrong can play havoc with the best of plans. I generally set up a system where waypoints are transferred from the chart plotter to a hand held and the the handheld waypoints are then plotted on a chart. I have twice found courses that attempted to sail through or very near small islands. I would also note that dredging barges can appear in the damndest places...and the radar image can be difficult to understand particularly against prominent background. Slow right down until we figure it out. Jim Donohue |
Bruce in Alaska wrote:
In article et, otnmbrd wrote: Jim Donohue wrote: Why with professional luddites like you and your ilk I am required for progress otn. As stated, "you just don't get it". In truth, I'm a prolific user of GPS, both the basic readout and connected to a chart plotter, making use of all the information it supplies. However, especially in the coastal waters I mainly traverse nowadays, it's NEVER my sole source of position information and in fact, plotting a GPS position isn't all that much quicker or necessarily as accurate as a simple radar range and bearing, or eyeball fix. The aside points out that the real amateur sailor with sufficient skill to cross oceans uses GPS otn...and have a likely non working celestial capability. It is in no way an excuse of any type...merely an observation on how life actually is. You likely don't like it otn but you really don't get a vote. You use your survey as an EXCUSE for not learning or using celestial. G By "non working" I assume you mean they have the ability but don't use it. That's their choice, just like it's the choice of many ship Masters making ocean crossings to require their people to occasionally take celestial fixes and when in sight of land or radar range, to take visual fixes as well as radar fixes and compare them to the GPS. I also note that in another reply, you are still not comfortable using radar for navigation.... that's too bad.... you're missing out on a great tool. otn I would like to add a simple note here. OTN talks about using Radar and the Mark One Eyeball to get position fixes while navigating in coastal and inshore waters. Ok, that is common practice, and has been for MANY years. Now consider the accuracy of those fixes, as compared with the accuracy of an Electronic Position Fixing Device. Mark One Eyeball.... Taking a sight with binocs even over a compass card will usually get a line within a degree or two, IF the guy is really good at it or is using one of those old WWII TBT's... Ok, now figure that your going to have to do that on at least two bearings, and better yet, three or four. Ok, now you have to go plot those bearings on the chart using the reverse bearing from the marker you sited on, and then figuring in the time difference between the bearings, and the speed of advance, of the vessel, and you don't get a REAL FIX, but an AREA of FIX that IS "Orders of Magnitude" bigger than the REALTIME GPS Fix. On the other hand, if you punched in in the wrong destination, or if the antennae fell off the GPS, an Eyeball LOP, however inaccurate, may show the problem. Radar..... Same thing here, except that your bearing will tend to be better, depending on the Horozontal Beamwidth of the antenna, and the distance, and area of the target which the bearing is to. Again, the AREA of the FIX will be smaller for the radar because the time to get the bearins, (two or more) will be shorter, but the plotting times and the speed of advance will be the same. Again the Area of fix will be "Orders of Magnitude" larger than the REALTIME GPS Fix. Again, if the GPS position is faulty in any way ... GPS Fix..... even with out WAAS, this should be in the 30 foot centered circle, and the speed of advance isn't even a problem due to the small amount of advance in the one second cycle times of GPS Calulations. The same can be said for LORAN-C with modern day Receivers, that have builtin Lat/LONG Calculators, especially if the route has been run before, and Know Anomalies in the TD's are already accounted for. Now all the above really is mostly not a GIANT Issue at 7 - 12 Knots, as there is always enough time to figure this all out. However, I defy anyone to show me how anything but a Very GOOD GPS Based Navigation System can be used on a Fast Ferry doing 35+ Knots inside Boston Harbour. I don't think the high speed ferries are allowed to do 35 knots inside the harbor. They are supposed to slow to 8 knots when the turn the corner into the inner harbor. The odd thing is that the Salem ferry doesn't use the main ship channel; it comes down the narrow side channel (Lower Middle) to save a few minutes. When its coming up your butt at 20 knots you have to just hope they know what they're doing. Speed KILLS, and the faster these guys go, the faster one of them is going to run the rest of us over, because the navigator isn't watching where he is going, because he is busy PLOTTING his position. Explain to me why this isn't a problem...... I don't think anyone would claim the the High Speed Ferry should turn off their GPS, but I do hope that they look out the window on occasion. Bruce in alaska |
You phrased the question badly. If everything is displaced along with the
rock it is rather straight forward to correct if you know of the error. If a rock is mischarted or uncharted you are correct. I think mischarted rocks are very rare. Mostly placed badly with everything else or missed completely. On the west coast we often deal with rapidly rising land masses...often at angles of more than 60 degrees with reference to the horizontal. You better be going real slow if you expect to get a depth sounder alert. This is actually a place where the GPS operator is at a disadvantage. A piloting operation is relative to local landmarks while GPS is absolute...so if the GPS guy is not aware of the error he has a problem in comparison to a piloting operator. On the other side of the equation in is reasonably easy for a gps operator to maintain someting close to optimal clearance of hard stuff. It is a complex and difficult task for a pilotage operator to do the same. Jim Donohue "Dave" wrote in message ... On Fri, 21 Jan 2005 08:15:10 -0800, "Jim Donohue" said: In many places you use the numbers from last time. Many of the numbers are published in guides or privately. You can also set up the course to minimize exposure. In general the errors are area wide. You work out the correction from known objects. You use radar and the bottom to assure yourself you did it correctly. Go slow when in doubt. Not responsive to the question. The question was: OK, how is that GPS going to help you avoid hitting that rock that's shown in the wrong place on the chart? The responsive answer would be that a GPS is as likely to send you into that uncharted rock as any other method, but there are other ways to avoid the rock that's somewhere other than where the chart shows it, like a depth sounder, and plotting a course well away from known rocks. |
On 21 Jan 2005 17:12:08 -0600, Dave wrote:
Yes. I well remember coming back from Cuttyhunk to Pt. Judith in a fog using RDF. Sure was glad to see the openings in the harbor of refuge breakwaters appear out of the fog. ========================== Ahhh yes, another sea story from the past. We did the same trip under similar circumstances back in the early 80s, probably when we still had the Westerly 28 and the kids were young. The closer we got to Pt Judith, the foggier it got until we were down to total pea soup conditions. Eventualy we could hear the surf on the breakwater and see the spray flying. Following the breakwater around to the western entrance, we DR'd our way to the channel buoys and upstream, where the fog eventually eased up a bit. We found a place to dock on the western side and shared a small dock with another sail boat. Talking with them later in the evening we learned they had been there 5 days waiting for the fog to lift! Next morning they were still there waiting. We proceeded on down to the breakwater, once again navigating in heavy fog, while dodging incoming ferrys and fishing boats. Several miles from the breakwater the fog lifted again and it was clear sailing all the way back into Long Island Sound. One of our family jokes is speculating on whether or not the other boat is still in Pt Judith waiting for the fog to lift. |
Bruce in Alaska wrote:
I would like to add a simple note here. OTN talks about using Radar and the Mark One Eyeball to get position fixes while navigating in coastal and inshore waters. Ok, that is common practice, and has been for MANY years. Now consider the accuracy of those fixes, as compared with the accuracy of an Electronic Position Fixing Device. BG Dang! I gotta find this place you guys are navigating through, that requires instant position data, within a few inches..... Mark One Eyeball.... Taking a sight with binocs even over a compass card will usually get a line within a degree or two, IF the guy is really good at it or is using one of those old WWII TBT's... Ok, now figure that your going to have to do that on at least two bearings, and better yet, three or four. Ok, now you have to go plot those bearings on the chart using the reverse bearing from the marker you sited on, and then figuring in the time difference between the bearings, and the speed of advance, of the vessel, and you don't get a REAL FIX, but an AREA of FIX that IS "Orders of Magnitude" bigger than the REALTIME GPS Fix. First off, the "Mark One Eyeball" method of navigation, can be many things. What you describe above, is just one of them. The accuracy of that same method can vary, from, exceeding GPS, to useless, but on average,will be well within the needed parameters to safely navigate an area under normal conditions. Needless to say, this method tends to suck in restricted visibility. With all due respect Bruce, it's obvious from your above that you are not all that familiar with the method you are discussing. Radar..... Same thing here, except that your bearing will tend to be better, depending on the Horozontal Beamwidth of the antenna, and the distance, and area of the target which the bearing is to. Again, the AREA of the FIX will be smaller for the radar because the time to get the bearins, (two or more) will be shorter, but the plotting times and the speed of advance will be the same. Again the Area of fix will be "Orders of Magnitude" larger than the REALTIME GPS Fix. Here, you are using only one of the methods available to you (in fact, the time consuming one). Sorry Bruce, but like Jim, your radar navigation needs work, also. Stand beside me under most coastal navigation areas in Alaska, take a reading on a GPS fix, at the same time I take a range and bearing via radar ... betcha I beat you plotting said fix and the only discrepancy between the two positions will revolve around how sharp my pencil was (unless of course the chart is in error, in which case my position is more apt to keep us out of trouble). BTW, forget the "speed of advance" junk .... it's a lame argument at the speeds we are talking about for most cruisers.... unless, of course, they've screwed up and gotten too close to a nav hazard, to begin with. GPS Fix..... even with out WAAS, this should be in the 30 foot centered circle, and the speed of advance isn't even a problem due to the small amount of advance in the one second cycle times of GPS Calulations. The same can be said for LORAN-C with modern day Receivers, that have builtin Lat/LONG Calculators, especially if the route has been run before, and Know Anomalies in the TD's are already accounted for. If, for the most part, your navigation requires you to be within a 30' centered circle, then I have to question your "route planning". Granted, there are times when you need precise distance information and you are navigating in narrow areas such a marina's and harbors where you have to work between docks, but in those areas, I'll take radar every time, because it doesn't care if the charted positions are correct. Now all the above really is mostly not a GIANT Issue at 7 - 12 Knots, as there is always enough time to figure this all out. However, I defy anyone to show me how anything but a Very GOOD GPS Based Navigation System can be used on a Fast Ferry doing 35+ Knots inside Boston Harbour. Speed KILLS, and the faster these guys go, the faster one of them is going to run the rest of us over, because the navigator isn't watching where he is going, because he is busy PLOTTING his position. Explain to me why this isn't a problem...... Sorry, haven't ridden any fast ferries in Boston. Rode the ones from Hyannis to Nantucket. From what I saw, most "general" navigation was done by "eyeball" and "radar"..... Why?....For those running a familiar route, it's faster and generally, more "spatial awareness" accurate for the operator. When a chart plotter is available, it's a fantastic third tool that frequently changes ranking in importance over the radar and eyeball..... so, in answer to your question, it IS a problem that various operators need address, though a simple GPS without a chart plotter is NOT the solution. otn |
Jim Donohue wrote:
SNIP On the other side of the equation in is reasonably easy for a gps operator to maintain someting close to optimal clearance of hard stuff. It is a complex and difficult task for a pilotage operator to do the same. Jim Donohue LOL Only part I think needs clarification. In coastal navigation (especially on much of the US West Coast), if the operator knows what he/she is doing, it is neither a complex or difficult task to maintain optimal clearance of hard stuff, under normal "piloting" conditions. otn |
And you mislead outrageously. It is of course quite simple on the west
coast. It is the nature of the coast. However we are dealing with a "otnmbrd" wrote in message nk.net... Jim Donohue wrote: SNIP On the other side of the equation in is reasonably easy for a gps operator to maintain someting close to optimal clearance of hard stuff. It is a complex and difficult task for a pilotage operator to do the same. Jim Donohue LOL Only part I think needs clarification. In coastal navigation (especially on much of the US West Coast), if the operator knows what he/she is doing, it is neither a complex or difficult task to maintain optimal clearance of hard stuff, under normal "piloting" conditions. otn While I do agree that the west is easier than the east one must still remember that piloting in navigation involves frequent or continuous determination of positon or a line of positon relative to geograhic points, and usually requiring need for close attention to the vessel's draft with respect to the depth of water. Iti is practiced in the vicinity of land, dangers, etc. and requires good judgement and almost constant attention and alertness on the part of the navigator. Which part don't you understand otn? Jim |
I'm a bit baffled by those who say you need nothing more than
GPS. Is GPS accurate? Of course it is. But make sure the GPS is set to the earth model the chart is. Oh, and make sure you never transpose numbers when entering waypoint data. One more small item...check the route to make sure there are no rocks/reefs in the way..the GPS will cheerfully run you aground. But you've already thought of those factors. Are DR nav methods, charts, hand bearings, etc. less accruate than GPS? Of course they are. Should one rely ONLY on GPS and chart plotters? If the answer is "yes", then that inplies you believe the electronics will never fail. And the IRS will never audit you..right? Is there something *wrong* with suggesting/teaching mulitple methods of navigation? I don't think GPS/radar have feelings...it won't mind if you confirm position by other means. Since I'm in a cranky mood, I'll tell you that the biggest risk to a boat is not deploying the Mark One Eyeball in close waters. For example, I've told students over and over again to do something as simple as looking behind them once in awhile when in the islands. But no, they look ahead for the waypoint coming up. Imagine their surprise when that big ferry or freighter toots it's horn a 1/4 mile aft. Happens a lot in these waters. Norm B |
Jim Donohue wrote:
And you mislead outrageously. It is of course quite simple on the west coast. It is the nature of the coast. However we are dealing with a Nothing misleading.... mayhaps beyond your comprehension? While I do agree that the west is easier than the east one must still remember that piloting in navigation involves frequent or continuous determination of positon or a line of positon relative to geograhic points, and usually requiring need for close attention to the vessel's draft with respect to the depth of water. Iti is practiced in the vicinity of land, dangers, etc. and requires good judgement and almost constant attention and alertness on the part of the navigator. Which part don't you understand otn? I understand it all quite well.... which part don't you understand? It doesn't matter what method you are using to determine your position under piloting conditions. The point is, (East coast, Gulf coast, West coast... I've done them all) that piloting, using eyeball or radar methods, is NOT necessarily all that more complex or difficult a problem to remain at optimal clearance to the hard stuff compared to GPS. All your arguments tend to do, is confirm that your piloting skills are limited, your radar skills are limited, your celestial skills are limited, since you keep looking for excuses to make GPS your sole source of navigation. Truth be known, your 25 years sailing and 12,000 miles coastal navigation is great and beyond what many have done, but obviously, like me, you're still learning, but I'm afraid you're not grasping many of the lessons. otn |
On Fri, 21 Jan 2005 20:08:04 GMT, Bruce in Alaska
wrote: In article et, otnmbrd wrote: Jim Donohue wrote: Why with professional luddites like you and your ilk I am required for progress otn. As stated, "you just don't get it". In truth, I'm a prolific user of GPS, both the basic readout and connected to a chart plotter, making use of all the information it supplies. However, especially in the coastal waters I mainly traverse nowadays, it's NEVER my sole source of position information and in fact, plotting a GPS position isn't all that much quicker or necessarily as accurate as a simple radar range and bearing, or eyeball fix. The aside points out that the real amateur sailor with sufficient skill to cross oceans uses GPS otn...and have a likely non working celestial capability. It is in no way an excuse of any type...merely an observation on how life actually is. You likely don't like it otn but you really don't get a vote. You use your survey as an EXCUSE for not learning or using celestial. G By "non working" I assume you mean they have the ability but don't use it. That's their choice, just like it's the choice of many ship Masters making ocean crossings to require their people to occasionally take celestial fixes and when in sight of land or radar range, to take visual fixes as well as radar fixes and compare them to the GPS. I also note that in another reply, you are still not comfortable using radar for navigation.... that's too bad.... you're missing out on a great tool. otn I would like to add a simple note here. OTN talks about using Radar and the Mark One Eyeball to get position fixes while navigating in coastal and inshore waters. Ok, that is common practice, and has been for MANY years. Now consider the accuracy of those fixes, as compared with the accuracy of an Electronic Position Fixing Device. Mark One Eyeball.... Taking a sight with binocs even over a compass card will usually get a line within a degree or two, IF the guy is really good at it or is using one of those old WWII TBT's... Ok, now figure that your going to have to do that on at least two bearings, and better yet, three or four. Ok, now you have to go plot those bearings on the chart using the reverse bearing from the marker you sited on, and then figuring in the time difference between the bearings, and the speed of advance, of the vessel, and you don't get a REAL FIX, but an AREA of FIX that IS "Orders of Magnitude" bigger than the REALTIME GPS Fix. Radar..... Same thing here, except that your bearing will tend to be better, depending on the Horozontal Beamwidth of the antenna, and the distance, and area of the target which the bearing is to. Again, the AREA of the FIX will be smaller for the radar because the time to get the bearins, (two or more) will be shorter, but the plotting times and the speed of advance will be the same. Again the Area of fix will be "Orders of Magnitude" larger than the REALTIME GPS Fix. GPS Fix..... even with out WAAS, this should be in the 30 foot centered circle, and the speed of advance isn't even a problem due to the small amount of advance in the one second cycle times of GPS Calulations. The same can be said for LORAN-C with modern day Receivers, that have builtin Lat/LONG Calculators, especially if the route has been run before, and Know Anomalies in the TD's are already accounted for. Now all the above really is mostly not a GIANT Issue at 7 - 12 Knots, as there is always enough time to figure this all out. However, I defy anyone to show me how anything but a Very GOOD GPS Based Navigation System can be used on a Fast Ferry doing 35+ Knots inside Boston Harbour. Speed KILLS, and the faster these guys go, the faster one of them is going to run the rest of us over, because the navigator isn't watching where he is going, because he is busy PLOTTING his position. Explain to me why this isn't a problem...... The ferry service between Stockhom and Helsinki was dependent on GPS with its own diferential setup back in the 1980s, years before the USCG had differential beacons, never mind WAAS. They were threading a lot of islands really fast in all visibilities, including zero. And their schedules were much faster than before GPS. Differential at that time was crucial for cancelling the effects of SA. Of course, they could survey the route themselves and verify the correspondence between GPS and chart. And, their differential system would have alarmed immediately on any GPS failure. Rodney Myrvaagnes J36 Gjo/a For your upscale SUV: Dingle-balls hand knit of natural Icelandic yarn |
Good Morning Roger!
I just read your thread. I was moved by it. I am a neophyte sailor who has been avidly sailing and living aboard for over six years on a small racing sloop (7.7m). I conclude from your edress that you're in New England. I know it won't be possible for me to come to you, so would you consider passing on " that something rich and rewarding" to someone eager to learn it as opposed to having it passing "from my life" and being lost forever. Although I have and use the new GPS technology I am eager to learn the old ways. My problem is I can't afford the schools for celestial navigation etc. If interested would you be interested in a "distance learning program" with me. Then perhaps in the future we can establish a time when I can come to your location over a long weekend or personal vacation to test and apply what I've learned. Maybe this is a crazy idea to you, but I hope you will find someone to whom you can "pass down'' this knowledge and experience so that it can be perpetuated instead of lost. Rico S/V OSAZZE "Roger Long" wrote in message ... The post about taking your charts with a grain of salt and using all available information brings up the conundrum I'm facing as I return to sailing after nearly 20 years. Most of my command time was in simple, traditional, boats. The most complex instrument on board was my usually watch. I didn't even have a depth sounder or speedometer and navigated clock and compass exactly as was done 100 years ago. Since I sailed in Maine, I saw a lot of fog and made a lot of long runs this way. Never in a boat have I felt more aware and in touch with my surroundings then when enveloped in that gray cocoon with buoys and ledges occasionally moving through it, usually right on schedule. The faint sound of a wave on rock, the darkening of the fog where a headland blocked the light, a change in wave patterns as I passed a gap in a protecting chain of islands or ledges, all helped confirm that my chart work was right. Some of the later boats I chartered had Loran but I never turned it on. I didn't want to be distracted by learning it and using the old ways was a big part of the enjoyment of cruising. I used (and taught when I was a piloting instructor) very simple methods that would be less likely to let me down when tired or busy. Instead of speed and distance calculations, I would just set my dividers to the boat's speed on the scale and then do everything in time. On one of my last charters, a hurricane threatened. We were way downeast and the owner insisted that we had to get sixty miles back to his mooring in dense fog instead of tucking the boat into a hole and riding it out. It was one of the thickest fogs I have ever seen. We ran through most of Fox Island Thoroughfare without seeing either shore. It was a memorable day. I learned how to fly airplanes a few years later and that put navigation in a whole new light. The plane had Loran and GPS but I refused to turn them on for the first three years so that I would develop the map and eyeball skills and a feel for the distances and speed. Now I use the magic boxes all the time but, in some ways, my situational awareness is less. I track a position that I can transfer to the paper map it the power fails but it is different. I used to be flying over the land and identified fixes below. Now I am flying over the map. You get lazy fast, especially with all the other things to attend to in an airplane. Now that I am about to return to boat piloting, I'm unsure about the place of GPS in my life. The old ways were a big part of cruising for me. Ride a cable car up a mountain in Switzerland and you may see people with ropes hanging by their fingernails trying to get the same place you are going. The rational is similar. I'd also like my video gaming kids to learn what the human mind can accomplish without the aid of a microprocessor. But, is it responsible? It certainly won't be seen as such if I ever hit anything. On the other hand, I know of many aircraft accidents that were clearly caused by the pilot trying to use the box instead of his mind. I always used to know where I was. I'm not sure narrowing it down with an electronic cursor will significantly increase my safety in most circumstances. The strongest rational I can see for relating my place in life to invisible satellites instead of the landscape I can see around me is backup for my macroprocessor. If I should fall overboard or become incapacitated, the kids can either tell the Coast Guard, "We're right here", or follow the cursor home. I'd like to think I could teach them to do the same thing the old way but, face it, they know about GPS, they aren't going to be very interested in learning that, "other stuff". I like gadgets though. I have an old aviation GPS that will give me latitude, longitude, and waypoints. I can't knowingly leave it ashore. I'll have to buy a marine unit for my new job as Harbormaster. I won't leave that behind either. Once I turn them on, I know I'll be hooked and something very rich and rewarding will have passed from my life forever. -- Roger Long |
Well, I'm touched by your comments.
However, there is nothing special about my knowledge. It's just the basics of coastal piloting and the foundation on which you should build your use of more advanced methods and tools. My original comment was that, when forced to rely on these methods alone because of economics and the availability of equipment at the time, I found myself forced into a heightened awareness of my surroundings and enjoying the simplicity. It's much like how a backpacker experiences his environment differently than someone who is driving through it. Just as there are times and places you shouldn't be walking, there are times and places that it would be foolish not to use GPS and other such tools now that they are universally available. I was never actually taught any of this. I just read about it and really paid attention when I first started going out in boats. You can do the same although learning from people who know more is never wasted. Finally, I know next to nothing about celestial. I'm strictly a coastal sailor. My big boat ocean time has always been as crew. I'm not in a position to take time to teach you anything personally and, as I said, it's no more that what a good piloting teacher would teach you first. The key is to navigate constantly, even when there is no question about your position. Read what you can, talk to everyone you can, and just sail in an alert fashion trying different things and paying attention to every clue you can. You should do fine. |
"otnmbrd" wrote in message nk.net... Jim Donohue wrote: There you go again leading the charge of the luddites otn. G I find it interesting/amusing, that from my comments below, and others of my past post that you are responding to, you consider the term "luddite" applicable to me. You comments on my skills show you lack of the mental attitude that leads to good navigation. No, my comments on your skills are based on reading your explanations of various navigational procedures and your conclusions regarding their viability based on your experience and skill or lack thereof. Ahh Bull otn...I use the same navigational procedures as you otn...and I understand why the work something you do not. The eye is a most important piece of navigation...unfortunately it does not work at all a great percentage of the time. Radar is fine under some circumstances but not very good under others. Only GPS works with accuracy all (for practical purposes)the time. It is therefore the first of many tools employed. You know what you know...and nobody is going to tell you different. G To a high degree, this is true. I also know what I don't know and where I may be weak on a subject in which case I listen or ask questions. You really are qualified for a deck officer role on the Royal Majestic. They showed exactly your sort of know it all attitude..why facts when you can postulate your opinion? G I believe you mean the Royal Majesty. You're right, I'm qualified to be that ship's Master. There is one difference between me and them however. Long ago, as we started getting more and more types and "complicated" electronic Nav aides on board, I started making it a habit to do "system" checks as I took over the watch, to be sure I was comfortable everything was functioning as advertised. When I became the "Boss", I made sure my officers did the same, and especially in piloting waters, that more than one system was being used and compared. Plus, having run that particular Safety Fairway, I would generally come up and confirm we had entered it correctly. Luckily technology and time over-rules you OTN. The march to GPS centric navigation is going to succeed whether you like it or not. Any the principle of position rather than bearing navigation is a certainty. And the ATONs are going away otn...25 years from now there will be practically none and all those will be in harbors or shifty situations like the ICW. And the magnetic compass is on its last legs. Ten years? Maybe 15? We will likely live long enough to see most of this occur and watch as you gnash your teeth otn. Jim I'll say it again. I love GPS. I make maximum use of GPS. I'm not gnashing my teeth, I'm waiting in anticipation of the next great Nav Aid that makes GPS outdated. The argument we are having and have always had is about Navigation safety. You want to make all navigation "GPS centric", in the sense that you discard all other forms of navigation and carry a bunch of GPS handhelds and spare batteries for when and if your main unit fails since most other forms of navigation cannot match GPS for overall speed and accuracy (note "overall"). And you again utterly misstate my position. GPS is the first skill taught...it should be the centerpiece of the navigation system. Then others. Certainly even the dullest of students can learn to check a chart position via eyeball or radar. Neither has the accuracy to verify the position and bnoth are compromised under some conditions but both are good checks for at least gross error. A fathometer provides a way to verify that the depth is where it should be for the position. Disagreement calls for caution. I use a second GPS to protect against a failure and to help resolve anomolies. I would not teach RDF or some of the more exotic piloting techniques. I would not teach time delay loran though I would point out that a working LORAN also provides a gross check on the GPS. I would not teach VOR/DME...though I have used VOR in navigating a boat. I would teach limited celestial for a student with the right mission. Now exactly what is it that you don't agree with and why otn? I, on the other hand, do not agree with relying solely on one SYSTEM!! (The Royal Majesty is a prime example of why)My experience/opinion is, you use ALL MEANS AVAILABLE to check and double check your position. The fact that those older systems may have drawbacks, may not be as easy, may not always be as accurate, may not always be available, is immaterial .... they have to save your butt only once, to make them well worth the learning. The Royal Majesty had at least five systems on which it was relying. It had GPS, Loran, Depthsounder, radar and eyeball. Its procedures required their use. The chief officer in fact lied about crucial visual sightings. You would have fit right in otn all the right system, an easy call but no nothing navigators who screwed it up. The message of the grounding was that given a sufficient level of incompetence you can screw up the simplest of tasks. It also demonstrated the level of utter incompetence available among the "cream" of professional navigators. As for the magnetic compass..... Lord willing you make it to a ripe old age with a sound mind. If you do, on your death bed, try to remember to ask someone if we are still using the magnetic compass in some form. My guess is that your response to their answer will be ..... Chit!! We will see otn. You really do not understand science. You simply can't project can you? Jim |
Jim Donohue wrote:
.... Ahh Bull otn...I use the same navigational procedures as you otn...and I understand why the work something you do not. The eye is a most important piece of navigation...unfortunately it does not work at all a great percentage of the time. Radar is fine under some circumstances but not very good under others. Only GPS works with accuracy all (for practical purposes)the time. It is therefore the first of many tools employed. Anyone who has been on a boat knows that a GPS *DOES NOT* for all practical purposes work all of the time. I've had a GPS fail several times, I've seen charting inaccuracies a number of times. Similar things have happened to almost every cruiser I know. None of these incidents were a major problem for me because I was using other techniques and was able to recognize the situation and compensate. The issue here is not which technique is the most accurate, or which should be used to the exclusion of the other. Continuing to cast it in these terms make you look like a jaxian fool. The issue is that you claimed it was foolish to teach someone basic piloting, even when the person was eager to learn. This attitude marks you as a complete fool, Jim. I hope I never meet one of your students on the water. .... And you again utterly misstate my position. GPS is the first skill taught...it should be the centerpiece of the navigation system. Then others. Certainly even the dullest of students can learn to check a chart position via eyeball or radar. Are you daft, man? Are you claiming now that piloting need not be taught because "even the dullest" can do it without training? And radar too? Bizarre, considering you've confessed to have weak radar skills! Neither has the accuracy to verify the position and bnoth are compromised under some conditions but both are good checks for at least gross error. A fathometer provides a way to verify that the depth is where it should be for the position. Disagreement calls for caution. True enough, however those that learn GPS first usually don't develop these skills. This is the crux of the issue. I use a second GPS to protect against a failure and to help resolve anomolies. I would not teach RDF or some of the more exotic piloting techniques. I would not teach time delay loran though I would point out that a working LORAN also provides a gross check on the GPS. I would not teach VOR/DME...though I have used VOR in navigating a boat. I would teach limited celestial for a student with the right mission. TD's, RDF and VOR are not the issue. Bringing them into the discussion shows you don't get it. Now exactly what is it that you don't agree with and why otn? You asserted that learning LOP's and DR was "utter nonsense." I think no one should be trusted with a GPS until the learn these basics. I, on the other hand, do not agree with relying solely on one SYSTEM!! (The Royal Majesty is a prime example of why)My experience/opinion is, you use ALL MEANS AVAILABLE to check and double check your position. The fact that those older systems may have drawbacks, may not be as easy, may not always be as accurate, may not always be available, is immaterial .... they have to save your butt only once, to make them well worth the learning. The Royal Majesty had at least five systems on which it was relying. It had GPS, Loran, Depthsounder, radar and eyeball. Its procedures required their use. The chief officer in fact lied about crucial visual sightings. You would have fit right in otn all the right system, an easy call but no nothing navigators who screwed it up. The message of the grounding was that given a sufficient level of incompetence you can screw up the simplest of tasks. It also demonstrated the level of utter incompetence available among the "cream" of professional navigators. The NTSB study blamed several "probable causes:" over reliance on GPS, and lack of training of the officers, and the failure to recognize the problem from other cues. This is a perfect example of problem with your approach. Claiming that your strategy works, but in this case they were incompetent is foolish. http://www.ntsb.gov/publictn/1997/MAR9701.pdf |
Jim Donohue wrote:
"otnmbrd" No, my comments on your skills are based on reading your explanations of various navigational procedures and your conclusions regarding their viability based on your experience and skill or lack thereof. Ahh Bull otn...I use the same navigational procedures as you otn...and I understand why the work something you do not. To be blunt .... what a stupid statement. Look. Jim, as I've said, I applaud your 25 years and 12,000 mi. of experience. However, because of my 40+ years (licensed, I'll ignore what came before) and hundreds of thousands of miles (conservatively) all over the world, plus my ongoing pilotage, you'll excuse me if I say .... BULL****!! I use methods you've never heard of, much less thought of. Understand them? LOL I've read your post ...... my statements about your skill level stands, and I understand things about most Nav SYSTEMS, you've never heard of. The eye is a most important piece of navigation...unfortunately it does not work at all a great percentage of the time. Bull****!! It doesn't matter if it's a clear day or a foggy day... the eye, looking at visual points, radar points, GPS points, Loran points.... then, using your brain, is the best interpreter of what's right or wrong. The problem is to make the maximum use of which SYSTEM is giving you the best information ..... and this can vary. Radar is fine under some circumstances but not very good under others. You've made it clear that your radar skills are limited. The problem is, that so many others also have your limited skills. One does not install a radar on their boat and become a "radar observer", so, in this respect, for you and most boaters, radar will not match GPS.... another of your statements that are a "tell" for me. Only GPS works with accuracy all (for practical purposes)the time. It is therefore the first of many tools employed. We could argue your "absolutes", but for the average boater, it would be meaningless. Sorry, but it's not the "first" of many tools .... starting from when you leave the dock, until you return. Hell, it's not necessarily even the most important. And you again utterly misstate my position. I don't think so. GPS is the first skill taught...it should be the centerpiece of the navigation system. No. What the hell good are those numbers if you can't make use of them? You best learn how to read a chart and plot Lat/Long first. Then it might be a good idea to learn what CMG means and how that relates to a compass. Then others. Yup, comes in handy knowing more than one way to plot a position and/or determine a route to clear hazards to your navigation. Certainly even the dullest of students can learn to check a chart position via eyeball or radar. True, but you've made it clear that for you ( and we must assume that many others are the same) this is not the easiest or most accurate method in your arsenal. Neither has the accuracy to verify the position Oh? Interesting. I'm running a range (either manmade or one I've determined, cause I can read a chart) and I pass abeam of a light house and put a mark on my chart. Will GPS be more accurate? Faster? and bnoth are compromised under some conditions but both are good checks for at least gross error. BG and you wonder why I doubt your skills. A fathometer provides a way to verify that the depth is where it should be for the position. Obviously, you've never used a fathometer for navigation. Disagreement calls for caution. I use a second GPS to protect against a failure and to help resolve anomolies. I use "ALL MEANS AVAILABLE". I would not teach RDF or some of the more exotic piloting techniques. I would not teach time delay loran though I would point out that a working LORAN also provides a gross check on the GPS. G I'd call that "teaching by amateurs, for amateurs". I would not teach VOR/DME...though I have used VOR in navigating a boat. Neither are Marine terms that I'm familiar with I would teach limited celestial for a student with the right mission. Depends on whether you believe in the "half assed" approach ..... obviously you do. Now exactly what is it that you don't agree with and why otn? BG Obviously quite a bit.... Why? VBG Because your attitude regarding navigation safety, sucks. Hey, personal opinion, others may vary. The Royal Majesty had at least five systems on which it was relying. It had GPS, Loran, Depthsounder, radar and eyeball. Its procedures required their use. The chief officer in fact lied about crucial visual sightings. You would have fit right in otn all the right system, an easy call but no nothing navigators who screwed it up. The message of the grounding was that given a sufficient level of incompetence you can screw up the simplest of tasks. It also demonstrated the level of utter incompetence available among the "cream" of professional navigators. ROFLMAO The above paragraph doesn't deserve any comment, other than this sentence and another hearty ROFLMAO !!!! OH hell, just for you, Jim. If you're gonna try to insult me, at least TRY to make some valid points. As for the magnetic compass..... Lord willing you make it to a ripe old age with a sound mind. If you do, on your death bed, try to remember to ask someone if we are still using the magnetic compass in some form. My guess is that your response to their answer will be ..... Chit!! We will see otn. You really do not understand science. You simply can't project can you? G I remember in my youth, the statements that the magnetic compass would soon disappear from ships because of the gyro compass .... guess what, Jim ............. otn otn |
Ok Guys. VOR/DME
VOR stands for "Very High Frequency Omnidirectional Range" DMS stands for "Distance Measuring Equipment" These are very useful when your boat is on a plane. Cheers JR otnmbrd wrote: Jim Donohue wrote: "otnmbrd" No, my comments on your skills are based on reading your explanations of various navigational procedures and your conclusions regarding their viability based on your experience and skill or lack thereof. Ahh Bull otn...I use the same navigational procedures as you otn...and I understand why the work something you do not. To be blunt .... what a stupid statement. Look. Jim, as I've said, I applaud your 25 years and 12,000 mi. of experience. However, because of my 40+ years (licensed, I'll ignore what came before) and hundreds of thousands of miles (conservatively) all over the world, plus my ongoing pilotage, you'll excuse me if I say .... BULL****!! I use methods you've never heard of, much less thought of. Understand them? LOL I've read your post ...... my statements about your skill level stands, and I understand things about most Nav SYSTEMS, you've never heard of. The eye is a most important piece of navigation...unfortunately it does not work at all a great percentage of the time. Bull****!! It doesn't matter if it's a clear day or a foggy day... the eye, looking at visual points, radar points, GPS points, Loran points.... then, using your brain, is the best interpreter of what's right or wrong. The problem is to make the maximum use of which SYSTEM is giving you the best information ..... and this can vary. Radar is fine under some circumstances but not very good under others. You've made it clear that your radar skills are limited. The problem is, that so many others also have your limited skills. One does not install a radar on their boat and become a "radar observer", so, in this respect, for you and most boaters, radar will not match GPS.... another of your statements that are a "tell" for me. Only GPS works with accuracy all (for practical purposes)the time. It is therefore the first of many tools employed. We could argue your "absolutes", but for the average boater, it would be meaningless. Sorry, but it's not the "first" of many tools .... starting from when you leave the dock, until you return. Hell, it's not necessarily even the most important. And you again utterly misstate my position. I don't think so. GPS is the first skill taught...it should be the centerpiece of the navigation system. No. What the hell good are those numbers if you can't make use of them? You best learn how to read a chart and plot Lat/Long first. Then it might be a good idea to learn what CMG means and how that relates to a compass. Then others. Yup, comes in handy knowing more than one way to plot a position and/or determine a route to clear hazards to your navigation. Certainly even the dullest of students can learn to check a chart position via eyeball or radar. True, but you've made it clear that for you ( and we must assume that many others are the same) this is not the easiest or most accurate method in your arsenal. Neither has the accuracy to verify the position Oh? Interesting. I'm running a range (either manmade or one I've determined, cause I can read a chart) and I pass abeam of a light house and put a mark on my chart. Will GPS be more accurate? Faster? and bnoth are compromised under some conditions but both are good checks for at least gross error. BG and you wonder why I doubt your skills. A fathometer provides a way to verify that the depth is where it should be for the position. Obviously, you've never used a fathometer for navigation. Disagreement calls for caution. I use a second GPS to protect against a failure and to help resolve anomolies. I use "ALL MEANS AVAILABLE". I would not teach RDF or some of the more exotic piloting techniques. I would not teach time delay loran though I would point out that a working LORAN also provides a gross check on the GPS. G I'd call that "teaching by amateurs, for amateurs". I would not teach VOR/DME...though I have used VOR in navigating a boat. Neither are Marine terms that I'm familiar with I would teach limited celestial for a student with the right mission. Depends on whether you believe in the "half assed" approach ..... obviously you do. Now exactly what is it that you don't agree with and why otn? BG Obviously quite a bit.... Why? VBG Because your attitude regarding navigation safety, sucks. Hey, personal opinion, others may vary. The Royal Majesty had at least five systems on which it was relying. It had GPS, Loran, Depthsounder, radar and eyeball. Its procedures required their use. The chief officer in fact lied about crucial visual sightings. You would have fit right in otn all the right system, an easy call but no nothing navigators who screwed it up. The message of the grounding was that given a sufficient level of incompetence you can screw up the simplest of tasks. It also demonstrated the level of utter incompetence available among the "cream" of professional navigators. ROFLMAO The above paragraph doesn't deserve any comment, other than this sentence and another hearty ROFLMAO !!!! OH hell, just for you, Jim. If you're gonna try to insult me, at least TRY to make some valid points. As for the magnetic compass..... Lord willing you make it to a ripe old age with a sound mind. If you do, on your death bed, try to remember to ask someone if we are still using the magnetic compass in some form. My guess is that your response to their answer will be ..... Chit!! We will see otn. You really do not understand science. You simply can't project can you? G I remember in my youth, the statements that the magnetic compass would soon disappear from ships because of the gyro compass .... guess what, Jim ............. otn otn |
And if you were sailing 25 years ago you would know that VOR was sometimes
installed on cruising sailboats. There are a number of places where VORs are located in areas useful to sailboats. Jim "Jr Gilbreath" wrote in message ... Ok Guys. VOR/DME VOR stands for "Very High Frequency Omnidirectional Range" DMS stands for "Distance Measuring Equipment" These are very useful when your boat is on a plane. Cheers JR otnmbrd wrote: Jim Donohue wrote: "otnmbrd" No, my comments on your skills are based on reading your explanations of various navigational procedures and your conclusions regarding their viability based on your experience and skill or lack thereof. Ahh Bull otn...I use the same navigational procedures as you otn...and I understand why the work something you do not. To be blunt .... what a stupid statement. Look. Jim, as I've said, I applaud your 25 years and 12,000 mi. of experience. However, because of my 40+ years (licensed, I'll ignore what came before) and hundreds of thousands of miles (conservatively) all over the world, plus my ongoing pilotage, you'll excuse me if I say .... BULL****!! I use methods you've never heard of, much less thought of. Understand them? LOL I've read your post ...... my statements about your skill level stands, and I understand things about most Nav SYSTEMS, you've never heard of. The eye is a most important piece of navigation...unfortunately it does not work at all a great percentage of the time. Bull****!! It doesn't matter if it's a clear day or a foggy day... the eye, looking at visual points, radar points, GPS points, Loran points.... then, using your brain, is the best interpreter of what's right or wrong. The problem is to make the maximum use of which SYSTEM is giving you the best information ..... and this can vary. Radar is fine under some circumstances but not very good under others. You've made it clear that your radar skills are limited. The problem is, that so many others also have your limited skills. One does not install a radar on their boat and become a "radar observer", so, in this respect, for you and most boaters, radar will not match GPS.... another of your statements that are a "tell" for me. Only GPS works with accuracy all (for practical purposes)the time. It is therefore the first of many tools employed. We could argue your "absolutes", but for the average boater, it would be meaningless. Sorry, but it's not the "first" of many tools .... starting from when you leave the dock, until you return. Hell, it's not necessarily even the most important. And you again utterly misstate my position. I don't think so. GPS is the first skill taught...it should be the centerpiece of the navigation system. No. What the hell good are those numbers if you can't make use of them? You best learn how to read a chart and plot Lat/Long first. Then it might be a good idea to learn what CMG means and how that relates to a compass. Then others. Yup, comes in handy knowing more than one way to plot a position and/or determine a route to clear hazards to your navigation. Certainly even the dullest of students can learn to check a chart position via eyeball or radar. True, but you've made it clear that for you ( and we must assume that many others are the same) this is not the easiest or most accurate method in your arsenal. Neither has the accuracy to verify the position Oh? Interesting. I'm running a range (either manmade or one I've determined, cause I can read a chart) and I pass abeam of a light house and put a mark on my chart. Will GPS be more accurate? Faster? and bnoth are compromised under some conditions but both are good checks for at least gross error. BG and you wonder why I doubt your skills. A fathometer provides a way to verify that the depth is where it should be for the position. Obviously, you've never used a fathometer for navigation. Disagreement calls for caution. I use a second GPS to protect against a failure and to help resolve anomolies. I use "ALL MEANS AVAILABLE". I would not teach RDF or some of the more exotic piloting techniques. I would not teach time delay loran though I would point out that a working LORAN also provides a gross check on the GPS. G I'd call that "teaching by amateurs, for amateurs". I would not teach VOR/DME...though I have used VOR in navigating a boat. Neither are Marine terms that I'm familiar with I would teach limited celestial for a student with the right mission. Depends on whether you believe in the "half assed" approach ..... obviously you do. Now exactly what is it that you don't agree with and why otn? BG Obviously quite a bit.... Why? VBG Because your attitude regarding navigation safety, sucks. Hey, personal opinion, others may vary. The Royal Majesty had at least five systems on which it was relying. It had GPS, Loran, Depthsounder, radar and eyeball. Its procedures required their use. The chief officer in fact lied about crucial visual sightings. You would have fit right in otn all the right system, an easy call but no nothing navigators who screwed it up. The message of the grounding was that given a sufficient level of incompetence you can screw up the simplest of tasks. It also demonstrated the level of utter incompetence available among the "cream" of professional navigators. ROFLMAO The above paragraph doesn't deserve any comment, other than this sentence and another hearty ROFLMAO !!!! OH hell, just for you, Jim. If you're gonna try to insult me, at least TRY to make some valid points. As for the magnetic compass..... Lord willing you make it to a ripe old age with a sound mind. If you do, on your death bed, try to remember to ask someone if we are still using the magnetic compass in some form. My guess is that your response to their answer will be ..... Chit!! We will see otn. You really do not understand science. You simply can't project can you? G I remember in my youth, the statements that the magnetic compass would soon disappear from ships because of the gyro compass .... guess what, Jim ............. otn otn |
"otnmbrd" wrote in message ink.net... Jim Donohue wrote: "otnmbrd" No, my comments on your skills are based on reading your explanations of various navigational procedures and your conclusions regarding their viability based on your experience and skill or lack thereof. Ahh Bull otn...I use the same navigational procedures as you otn...and I understand why the work something you do not. To be blunt .... what a stupid statement. Look. Jim, as I've said, I applaud your 25 years and 12,000 mi. of experience. However, because of my 40+ years (licensed, I'll ignore what came before) and hundreds of thousands of miles (conservatively) all over the world, plus my ongoing pilotage, you'll excuse me if I say .... BULL****!! I use methods you've never heard of, much less thought of. Understand them? LOL I've read your post ...... my statements about your skill level stands, and I understand things about most Nav SYSTEMS, you've never heard of. Ohhh you use something besides GPS and DR and LORAN and RADAR? Perhaps you might have a claim on a gyro compass...but other than that I doubt you use anything different than I do. I would agree that you likely use them at a higher skill level and more facilely than I...but that does not change the fact that we rely on the same technology for the same purpose. Then again I suspect I understood some of it better than you do. Can't tell that for sure but with your closed mind I doubt you innovate well under pressure. The eye is a most important piece of navigation...unfortunately it does not work at all a great percentage of the time. Bull****!! It doesn't matter if it's a clear day or a foggy day... the eye, looking at visual points, radar points, GPS points, Loran points.... then, using your brain, is the best interpreter of what's right or wrong. The problem is to make the maximum use of which SYSTEM is giving you the best information ..... and this can vary. You continue to confuse different issues. The eye as an instrument in navigation is a useful one for piloting situations...particularly as a continuous check. Its use in this way is however limited by the visibility conditions. The eye also serves as an input device to the human but that is a different use then navigation. Don' obfuscate the issue with the second use. Radar is fine under some circumstances but not very good under others. You've made it clear that your radar skills are limited. The problem is, that so many others also have your limited skills. One does not install a radar on their boat and become a "radar observer", so, in this respect, for you and most boaters, radar will not match GPS.... another of your statements that are a "tell" for me. And you have made it clear you do not understand the well documented and science based limitations of radar. This probably makes you a worse sailor than most otn. Your view that radar always provides an accurate picture of the physical world is a dangereous one likely to lead to bad outcomes. To rely upon radar rather than a GPS for your primary positon is foolish under most circumstances I can imagine. Ohh I am sure you can set up some weird harbor situation where radar is effective and GPS is not otn...but that just proves the old adage that there are exceptions to all rules. Now if a positon difference exists between the radar and your chart plotter...you now have doubt and have to use the brain to sort it out. Only GPS works with accuracy all (for practical purposes)the time. It is therefore the first of many tools employed. We could argue your "absolutes", but for the average boater, it would be meaningless. Sorry, but it's not the "first" of many tools .... starting from when you leave the dock, until you return. Hell, it's not necessarily even the most important. We are talking navigation otn..navigation. Navigation is not the only task in boating. And you again utterly misstate my position. I don't think so. GPS is the first skill taught...it should be the centerpiece of the navigation system. No. What the hell good are those numbers if you can't make use of them? You best learn how to read a chart and plot Lat/Long first. Then it might be a good idea to learn what CMG means and how that relates to a compass. I have said repeatedly that the first thing is reading and interpreting a chart. I simply believe that you do that in view of a GPS being used to direct the vessel. CMG is as common in GPS as in DR. Then others. Yup, comes in handy knowing more than one way to plot a position and/or determine a route to clear hazards to your navigation. Again you deliberately mis-state my position. You obviously read badly. Certainly even the dullest of students can learn to check a chart position via eyeball or radar. True, but you've made it clear that for you ( and we must assume that many others are the same) this is not the easiest or most accurate method in your arsenal. I have said no such thing. You can't deal with my arguments otn so you misstate them. Neither has the accuracy to verify the position Oh? Interesting. I'm running a range (either manmade or one I've determined, cause I can read a chart) and I pass abeam of a light house and put a mark on my chart. Will GPS be more accurate? Faster? Yes the GPS will be more accurate and faster. If the GPS does not agree with the range/lighthouse you now have doubt and have to sort it. Get used to it otn...in five or ten years that light is gone. and bnoth are compromised under some conditions but both are good checks for at least gross error. BG and you wonder why I doubt your skills. A fathometer provides a way to verify that the depth is where it should be for the position. Obviously, you've never used a fathometer for navigation. Oh, and where did I say that? You don't watch depth at your positon otn? You are so secure in your visual/radar pilotage that depth is not an issue? Yeah right. I did not say that the only use for a fathometer is checking position...but it is a good one. Disagreement calls for caution. I use a second GPS to protect against a failure and to help resolve anomolies. I use "ALL MEANS AVAILABLE". And so do I...well not quite...I don't generally fire up an antiquated RDF and locate off the local radio stations. I could. But it is time consuming and unlikely to provide much information except under unusual circumstances. I suppose under these circumstances you would assign a crew member to operate the RDF and feed you cross checks but I do not have unlimited resources on my bridge...such as it is. I would not teach RDF or some of the more exotic piloting techniques. I would not teach time delay loran though I would point out that a working LORAN also provides a gross check on the GPS. G I'd call that "teaching by amateurs, for amateurs". I am sure you would...but you do that otn. Reach down into your mind and see if you can explain what you would do instead otn. I would not teach VOR/DME...though I have used VOR in navigating a boat. Neither are Marine terms that I'm familiar with I would teach limited celestial for a student with the right mission. Depends on whether you believe in the "half assed" approach ..... obviously you do. And what is your "whole assed" approach otn? Now exactly what is it that you don't agree with and why otn? BG Obviously quite a bit.... Why? VBG Because your attitude regarding navigation safety, sucks. Hey, personal opinion, others may vary. The Royal Majesty had at least five systems on which it was relying. It had GPS, Loran, Depthsounder, radar and eyeball. Its procedures required their use. The chief officer in fact lied about crucial visual sightings. You would have fit right in otn all the right system, an easy call but no nothing navigators who screwed it up. The message of the grounding was that given a sufficient level of incompetence you can screw up the simplest of tasks. It also demonstrated the level of utter incompetence available among the "cream" of professional navigators. ROFLMAO The above paragraph doesn't deserve any comment, other than this sentence and another hearty ROFLMAO !!!! OH hell, just for you, Jim. If you're gonna try to insult me, at least TRY to make some valid points. Why I think your closed mind fits very well on the bridge otn...you know what you know...you don't know why it is true or understand the alternatives...but you know what you know. As for the magnetic compass..... Lord willing you make it to a ripe old age with a sound mind. If you do, on your death bed, try to remember to ask someone if we are still using the magnetic compass in some form. My guess is that your response to their answer will be ..... Chit!! We will see otn. You really do not understand science. You simply can't project can you? G I remember in my youth, the statements that the magnetic compass would soon disappear from ships because of the gyro compass .... guess what, Jim ............. otn otn |
Jr Gilbreath wrote:
Ok Guys. VOR/DME VOR stands for "Very High Frequency Omnidirectional Range" DMS stands for "Distance Measuring Equipment" These are very useful when your boat is on a plane. Cheers JR Back in the early 80's I sailed out of Niagara on Lake Ontario. I had a VOR nav system that was made for marine purposes. I don't recall the manufacturer but it was about the size of an old turntable and had a large compass dial on the top. We could tune in radio station broacast towers all around the lake and the indicator would show the go-to arrow against the compass rose beneath. Quite handy. But still you had to know DR first. Fast forward to 2005. GPS is great, until the power fails... |
"Jeff Morris" wrote in message ... Jim Donohue wrote: ... Ahh Bull otn...I use the same navigational procedures as you otn...and I understand why the work something you do not. The eye is a most important piece of navigation...unfortunately it does not work at all a great percentage of the time. Radar is fine under some circumstances but not very good under others. Only GPS works with accuracy all (for practical purposes)the time. It is therefore the first of many tools employed. Anyone who has been on a boat knows that a GPS *DOES NOT* for all practical purposes work all of the time. I've had a GPS fail several times, I've seen charting inaccuracies a number of times. Similar things have happened to almost every cruiser I know. You lead an unlucky life. I have never seen a significant outage of the GPS. I follow the tech literature on the subject. Aside from deliberate military actions the outages are very few, far between, and limited in time duration. As I said I have never seen one. It is of course possible that you have a source of interference on your boat. That does happen. It is one of the reasons that multiple GPSs are sensible. Different devices have different weaknesses. I am sure there are also some specific locations that have a multi-path problem. Again though few and far between. GPS ain't perfect but it is very close. Done with redundant instruments on the open sea it is, for all practical purposes, perfect. The present cruiser population is certainly and effectively completely dependent on GPS for off shore navigation. At this point I don't think there are many exceptions left. I have not come across a report of a significant problem with that in a long time. Charting inaccuracies are chart problems very close to completely. Without gps they are hard to detect. The ones on the West coast of Mexico however are detectible with a good LORAN. None of these incidents were a major problem for me because I was using other techniques and was able to recognize the situation and compensate. The issue here is not which technique is the most accurate, or which should be used to the exclusion of the other. Continuing to cast it in these terms make you look like a jaxian fool. One uses all reasonable methods available. The first and primary of these is GPS. Your inablity to understand this simple statement is almost jaxian. The issue is that you claimed it was foolish to teach someone basic piloting, even when the person was eager to learn. This attitude marks you as a complete fool, Jim. I hope I never meet one of your students on the water. No my argument was that basic navigation...not piloting...was better taught with GPS as the primary technique. It was in response to an individual teaching basic navigation with electronic aids removed. It is even possible that the individual involved and I would end at the same end point. Just different routings. ... And you again utterly misstate my position. GPS is the first skill taught...it should be the centerpiece of the navigation system. Then others. Certainly even the dullest of students can learn to check a chart position via eyeball or radar. Are you daft, man? Are you claiming now that piloting need not be taught because "even the dullest" can do it without training? And radar too? Bizarre, considering you've confessed to have weak radar skills! Listen carefully. Pilotage is important. One teaches navigation with the GPS first. The first portion of that instruction is the use of charts. A current student however should learn with the GPS positon centric techniques rather than the LOP techniques of conventional DR. Yes eventually these get taught also...but secondary to what is the real world. Neither has the accuracy to verify the position and bnoth are compromised under some conditions but both are good checks for at least gross error. A fathometer provides a way to verify that the depth is where it should be for the position. Disagreement calls for caution. True enough, however those that learn GPS first usually don't develop these skills. This is the crux of the issue. I use a second GPS to protect against a failure and to help resolve anomolies. I would not teach RDF or some of the more exotic piloting techniques. I would not teach time delay loran though I would point out that a working LORAN also provides a gross check on the GPS. I would not teach VOR/DME...though I have used VOR in navigating a boat. I would teach limited celestial for a student with the right mission. TD's, RDF and VOR are not the issue. Bringing them into the discussion shows you don't get it. Now exactly what is it that you don't agree with and why otn? You asserted that learning LOP's and DR was "utter nonsense." I think no one should be trusted with a GPS until the learn these basics. Uhhh where did it state that learning LOPs and DR was "utter nonsense"? I think I made such a comment about teaching a student navigation with such techniques emphasized to the exclusion of electronic navigation. Still do. You correctly point out that it will be difficult to teach DR/LOP after one learns electronic navigation. That is because it is difficult to convince the student that sufficient value exists in such techniques. You deal with this value problem by teaching DR/LOP first. I claim simple that this in no way prevents the knowledge of DR/LOP going away real fast. I think we need to develop that set of DR/LOP skills that will actually stick after electronic navigation is learned. If we can't develop such a set and convince the newby of value then the outcome is the same. I stress the electronic navigation first because I think it more important they do that well than that they master an initial set of techniques they will abandon upon learning the electronic version. First good at the primary system then good at the secondaries. I introduce VOR/DME and RDF merely to demonstrate that we really don't propose to teach all available navigation techniques...only those that we believe useful and reasonable. I, on the other hand, do not agree with relying solely on one SYSTEM!! (The Royal Majesty is a prime example of why)My experience/opinion is, you use ALL MEANS AVAILABLE to check and double check your position. The fact that those older systems may have drawbacks, may not be as easy, may not always be as accurate, may not always be available, is immaterial .... they have to save your butt only once, to make them well worth the learning. The Royal Majesty had at least five systems on which it was relying. It had GPS, Loran, Depthsounder, radar and eyeball. Its procedures required their use. The chief officer in fact lied about crucial visual sightings. You would have fit right in otn all the right system, an easy call but no nothing navigators who screwed it up. The message of the grounding was that given a sufficient level of incompetence you can screw up the simplest of tasks. It also demonstrated the level of utter incompetence available among the "cream" of professional navigators. The NTSB study blamed several "probable causes:" over reliance on GPS, and lack of training of the officers, and the failure to recognize the problem from other cues. This is a perfect example of problem with your approach. Claiming that your strategy works, but in this case they were incompetent is foolish. http://www.ntsb.gov/publictn/1997/MAR9701.pdf I am reasonably familiar with the report. Find for me any mention of over reliance on GPS. It does find fault with over reliance on the automatic features of integrated bridge systems. It also discusses flaws in the design of such systems. I agree that total reliance on a single GPS is not wise. I generally run three...and two are active in the process to try to avoid the entry errors that I believe are the worst problems with GPS navigation. When the europeans get their system operative or the Russians complete theirs I will almost certainly run one GPS off another system. I will also use other inputs like depthsounders and radar to help prevent errors. Jim |
I'm kind of surprised that worked. VOR's are so hard to pick up on
the ground that they broadcast a special test frequency at airports for calibrating them. The signals are optimized for pick up in the air and don't seem to hug the ground very well. Sometimes, you'll even lose them in the air at low altitudes. -- Roger Long "prodigal1" wrote in message ... Jr Gilbreath wrote: Ok Guys. VOR/DME VOR stands for "Very High Frequency Omnidirectional Range" DMS stands for "Distance Measuring Equipment" These are very useful when your boat is on a plane. Cheers JR Back in the early 80's I sailed out of Niagara on Lake Ontario. I had a VOR nav system that was made for marine purposes. I don't recall the manufacturer but it was about the size of an old turntable and had a large compass dial on the top. We could tune in radio station broacast towers all around the lake and the indicator would show the go-to arrow against the compass rose beneath. Quite handy. But still you had to know DR first. Fast forward to 2005. GPS is great, until the power fails... |
On Mon, 24 Jan 2005 06:50:13 -0500, prodigal1 wrote:
I had a VOR nav system that was made for marine purposes. I don't recall the manufacturer but it was about the size of an old turntable and had a large compass dial on the top. We could tune in radio station broacast towers all around the lake and the indicator would show the go-to arrow against the compass rose beneath. ==================================== What you describe is not a VOR but rather an RDF. VOR is an aircraft system that gives a direct bearing to the beacon transmitter without need to rotate the receiving antenna. |
On Mon, 24 Jan 2005 13:57:25 GMT, "Roger Long"
wrote: I'm kind of surprised that worked. VOR's are so hard to pick up on the ground that they broadcast a special test frequency at airports for calibrating them. The signals are optimized for pick up in the air and don't seem to hug the ground very well. Sometimes, you'll even lose them in the air at low altitudes. ==================================== They were more popular on sailboats where mast height gives some additional range. They were popular for coastal cruisers and racers for a while because they were easier to use and more accurate than an RDF. One of the biggest problems with RDF was that in addition to determining bearing to the transmitter, you also needed an accurate boat heading at the same instant. I would take the RDF bearing and yell "mark" at the moment I had it. My wife had to note the compass heading at the same time that I yelled. We would repeat this several times and average the results. If you were plus or minus 2 or 3 degrees, that was a good LOP. On a 3 bearing fix from 10 miles offshore, your uncertainty triangle was frequently 1 mile on each side. With VOR, all you had to do was read the bearing from the dial, usually accurate to about 1 or 2 degrees. |
Rico,
One of the best books ever written on "the old ways" is available for free on the internet: http://www.irbs.com/bowditch/ ============================================= On Sat, 22 Jan 2005 10:05:31 -0600, "Rico" wrote: Good Morning Roger! I just read your thread. I was moved by it. I am a neophyte sailor who has been avidly sailing and living aboard for over six years on a small racing sloop (7.7m). I conclude from your edress that you're in New England. I know it won't be possible for me to come to you, so would you consider passing on " that something rich and rewarding" to someone eager to learn it as opposed to having it passing "from my life" and being lost forever. Although I have and use the new GPS technology I am eager to learn the old ways. My problem is I can't afford the schools for celestial navigation etc. If interested would you be interested in a "distance learning program" with me. Then perhaps in the future we can establish a time when I can come to your location over a long weekend or personal vacation to test and apply what I've learned. Maybe this is a crazy idea to you, but I hope you will find someone to whom you can "pass down'' this knowledge and experience so that it can be perpetuated instead of lost. Rico S/V OSAZZE "Roger Long" wrote in message .. . The post about taking your charts with a grain of salt and using all available information brings up the conundrum I'm facing as I return to sailing after nearly 20 years. Most of my command time was in simple, traditional, boats. The most complex instrument on board was my usually watch. I didn't even have a depth sounder or speedometer and navigated clock and compass exactly as was done 100 years ago. Since I sailed in Maine, I saw a lot of fog and made a lot of long runs this way. Never in a boat have I felt more aware and in touch with my surroundings then when enveloped in that gray cocoon with buoys and ledges occasionally moving through it, usually right on schedule. The faint sound of a wave on rock, the darkening of the fog where a headland blocked the light, a change in wave patterns as I passed a gap in a protecting chain of islands or ledges, all helped confirm that my chart work was right. Some of the later boats I chartered had Loran but I never turned it on. I didn't want to be distracted by learning it and using the old ways was a big part of the enjoyment of cruising. I used (and taught when I was a piloting instructor) very simple methods that would be less likely to let me down when tired or busy. Instead of speed and distance calculations, I would just set my dividers to the boat's speed on the scale and then do everything in time. On one of my last charters, a hurricane threatened. We were way downeast and the owner insisted that we had to get sixty miles back to his mooring in dense fog instead of tucking the boat into a hole and riding it out. It was one of the thickest fogs I have ever seen. We ran through most of Fox Island Thoroughfare without seeing either shore. It was a memorable day. I learned how to fly airplanes a few years later and that put navigation in a whole new light. The plane had Loran and GPS but I refused to turn them on for the first three years so that I would develop the map and eyeball skills and a feel for the distances and speed. Now I use the magic boxes all the time but, in some ways, my situational awareness is less. I track a position that I can transfer to the paper map it the power fails but it is different. I used to be flying over the land and identified fixes below. Now I am flying over the map. You get lazy fast, especially with all the other things to attend to in an airplane. Now that I am about to return to boat piloting, I'm unsure about the place of GPS in my life. The old ways were a big part of cruising for me. Ride a cable car up a mountain in Switzerland and you may see people with ropes hanging by their fingernails trying to get the same place you are going. The rational is similar. I'd also like my video gaming kids to learn what the human mind can accomplish without the aid of a microprocessor. But, is it responsible? It certainly won't be seen as such if I ever hit anything. On the other hand, I know of many aircraft accidents that were clearly caused by the pilot trying to use the box instead of his mind. I always used to know where I was. I'm not sure narrowing it down with an electronic cursor will significantly increase my safety in most circumstances. The strongest rational I can see for relating my place in life to invisible satellites instead of the landscape I can see around me is backup for my macroprocessor. If I should fall overboard or become incapacitated, the kids can either tell the Coast Guard, "We're right here", or follow the cursor home. I'd like to think I could teach them to do the same thing the old way but, face it, they know about GPS, they aren't going to be very interested in learning that, "other stuff". I like gadgets though. I have an old aviation GPS that will give me latitude, longitude, and waypoints. I can't knowingly leave it ashore. I'll have to buy a marine unit for my new job as Harbormaster. I won't leave that behind either. Once I turn them on, I know I'll be hooked and something very rich and rewarding will have passed from my life forever. -- Roger Long |
On Mon, 17 Jan 2005 12:18:02 GMT, "Roger Long"
wrote: Now that I am about to return to boat piloting, I'm unsure about the place of GPS in my life. The old ways were a big part of cruising for me. Ride a cable car up a mountain in Switzerland and you may see people with ropes hanging by their fingernails trying to get the same place you are going. The rational is similar. I'd also like my video gaming kids to learn what the human mind can accomplish without the aid of a microprocessor. You have a good approach. Consider using the GPS for confirmation only of your DR plots and running fixes when conditions are less than ideal. Keep using the same safety margins as when you are doing straight pilotage. I find I use the GPS mostly for SOG, to alert me to set and drift due to non-obvious currents, and for ETAs, at which it is handy for placating the crew G. Lat/lon is helpful in confirming my navigation, not replacing it. It does allow me to "sneak up" on things somewhat more safely, like a buoy marking a shoal (not too shoal for me, but close). In fog, the GPS allows me to know whether I'm on the "good side" of it, and as I get close to its actual position (noted as a waypoint and not quite correctly noted on the chart, BTW), I can ignore the GPS and "listen" for the buoy's creaking and splash. So I keep the old skills up. The GPS is like a jackline: just another safety tool that is only very occasionally a life saver. Offshore, I'd go celestial and use GPS to obtain times and to see if my errors were shrinking. R. |
Jim Donohue wrote:
Ohhh you use something besides GPS and DR and LORAN and RADAR? G I'm assuming you just mentioned those 4 for brevity. Perhaps you might have a claim on a gyro compass...but other than that I doubt you use anything different than I do. I would agree that you likely use them at a higher skill level and more facilely than I...but that does not change the fact that we rely on the same technology for the same purpose. Then again I suspect I understood some of it better than you do. Can't tell that for sure but with your closed mind I doubt you innovate well under pressure. I don't doubt in the least that you may have a greater understanding of some of the "engineering" involved with the electronic systems in discussion. However, where their practical application is concerned..... In that vein, I suspect you consider my mind closed because I disagree with your approach and reasoning that goes with that approach. You continue to confuse different issues. The eye as an instrument in navigation is a useful one for piloting situations...particularly as a continuous check. Its use in this way is however limited by the visibility conditions. The eye also serves as an input device to the human but that is a different use then navigation. Don' obfuscate the issue with the second use. G Then don't denigrate the use of the "eye" because on some days the visibility may be less than perfect. And you have made it clear you do not understand the well documented and science based limitations of radar. This probably makes you a worse sailor than most otn. Your view that radar always provides an accurate picture of the physical world is a dangereous one likely to lead to bad outcomes. To rely upon radar rather than a GPS for your primary positon is foolish under most circumstances I can imagine. Ohh I am sure you can set up some weird harbor situation where radar is effective and GPS is not otn...but that just proves the old adage that there are exceptions to all rules. Now if a positon difference exists between the radar and your chart plotter...you now have doubt and have to use the brain to sort it out. NO Jim. I fully understand the documented and science based limitations of radar. More importantly, I also understand the operator/observer limitations and plusses. I have never stated that radar ALWAYS provides an accurate picture ... it can't for many obvious reasons. However, in the hands of a competent operator/observer, radar becomes a highly accurate tool of navigation and in many cases a better "primary" tool for positions due to it's relatively quick update and "birds eye" view. I don't need to set up some weird harbor condition to show this, G as I frequently use radar as my primary and GPS as my secondary. We are talking navigation otn..navigation. Navigation is not the only task in boating. I was keeping to the subject at hand. snip I was going to comment on a few issues, but then I came to this next. Oh? Interesting. I'm running a range (either manmade or one I've determined, cause I can read a chart) and I pass abeam of a light house and put a mark on my chart. Will GPS be more accurate? Faster? Yes the GPS will be more accurate and faster. If the GPS does not agree with the range/lighthouse you now have doubt and have to sort it. Get used to it otn...in five or ten years that light is gone. Interesting. Please explain how GPS will be faster and/or more accurate. Which is most apt to show an error which may cause you problems? As for the last sentence .... Jim, I chose a "lighthouse". I could have said "buoy", but we both know why that wouldn't be good. I could also have said a point of land, a charted building, etc.. Hopefully, those with seagoing experience who understand the value of lighthouses even in this "GPS Centric" age will keep that house operating. Oh, and where did I say that? You don't watch depth at your positon otn? You are so secure in your visual/radar pilotage that depth is not an issue? Yeah right. I did not say that the only use for a fathometer is checking position...but it is a good one. Sheesh, and you say I misstate and misread. Jim, I said obviously you've never used the fathometer for "navigation". I was referring to the practice of determining your position based on soundings alone. It's one of those "innovations" you use, under pressure. And so do I...well not quite...I don't generally fire up an antiquated RDF and locate off the local radio stations. I could. But it is time consuming and unlikely to provide much information except under unusual circumstances. Hey, sometimes that's all you need. I suppose under these circumstances you would assign a crew member to operate the RDF and feed you cross checks but I do not have unlimited resources on my bridge...such as it is. G Using an RDF is like reading a Radar. I doubt most young Mates would be too competent, so if it got to that point I'd probably leave them behind the Radar, etc., while I did the RDF..... course, with all else available, I must all ready be in deep doodoo if I'm having to revert to that, but hey, sometimes that's all you need. G I'd call that "teaching by amateurs, for amateurs". I am sure you would...but you do that otn. Reach down into your mind and see if you can explain what you would do instead otn. I don't like your basic approach "start at the top and work backwards". I still firmly believe in starting at the bottom and working up gives a far better understanding of the issues involved. Depends on whether you believe in the "half assed" approach ..... obviously you do. And what is your "whole assed" approach otn? See answer above. Why I think your closed mind fits very well on the bridge otn...you know what you know...you don't know why it is true or understand the alternatives...but you know what you know. Sometimes, your conclusions astound me. This is one of them. The Captain and Mates on the Majesty screwed up in many ways. The central screw-up was being "GPS Centric". They relied solely on the GPS and it's high end plotter and auto pilot, when all around them were tools which were showing that a problem existed, if they'd just used them. otn |
"Steven Shelikoff" wrote in message ... On Mon, 24 Jan 2005 04:49:38 -0800, "Jim Donohue" wrote: The present cruiser population is certainly and effectively completely dependent on GPS for off shore navigation. At this point I don't think there are many exceptions left. I have not come across a report of a significant problem with that in a long time. I doubt this very much. I.e., I severly doubt that if GPS shut down tomorrow, the present cruiser population who are off shore are suddenly all doomed to die because they don't have any other means of navigation. Maybe one or two, but the percentage is tiny. And I agree and never said otherwise. Most will adopt quickly. Many have celestial skills though likely very rusty. DR will suffice for the rest. I would however expect the accident rate to go up by an order of magnitude or more. Still a small percentage though. [...] One uses all reasonable methods available. The first and primary of these is GPS. Your inablity to understand this simple statement is almost jaxian. Wow, we're making progress. So you finally do agree with the rest of everyone else here that, while it's fine to have GPS as a primary means of navigation, relying totally on GPS without checking it against other reasonable methods of navigation is foolhardy. Steve Bull Steve...you Luddites simply read to confirm your opinions. I have never anywhere suggested any such thing. Did you notice that Jeff Morris cannot even read an NTSB report without getting it wrong? The actual conclusions do not meet his pre-conception so he simply misquotes them. You technophobes are all alike. Jim |
"otnmbrd" wrote in message ink.net... Jim Donohue wrote: "otnmbrd" No, my comments on your skills are based on reading your explanations of various navigational procedures and your conclusions regarding their viability based on your experience and skill or lack thereof. Snip I would not teach VOR/DME...though I have used VOR in navigating a boat. Neither are Marine terms that I'm familiar with And here is one where your skills are clearly less than mine. I would be very comfortable doing VOR navigation under approprate circumstances. snip Jim |
Jim Donohue wrote:
"otnmbrd" wrote in message ink.net... Jim Donohue wrote: "otnmbrd" No, my comments on your skills are based on reading your explanations of various navigational procedures and your conclusions regarding their viability based on your experience and skill or lack thereof. Snip I would not teach VOR/DME...though I have used VOR in navigating a boat. Neither are Marine terms that I'm familiar with And here is one where your skills are clearly less than mine. I would be very comfortable doing VOR navigation under approprate circumstances. snip Jim I bow to your expertise on this subject. otn |
On Mon, 24 Jan 2005 19:10:28 GMT, otnmbrd
wrote: Why I think your closed mind fits very well on the bridge otn...you know what you know...you don't know why it is true or understand the alternatives...but you know what you know. Sometimes, your conclusions astound me. This is one of them. The Captain and Mates on the Majesty screwed up in many ways. The central screw-up was being "GPS Centric". They relied solely on the GPS and it's high end plotter and auto pilot, when all around them were tools which were showing that a problem existed, if they'd just used them. Actually, the GPS was not in use. It was just that nobody thought to check if it was for 600 nm. Reconnecting the antenna would have solved the problem, as would have several of the other things nobody bothered to check. They were "integrated-bridge-system centric." A significant difference. Rodney Myrvaagnes J36 Gjo/a "If any question why we died Tell them, because our fathers lied." --Kipling |
Jim Donohue wrote:
"Jeff Morris" wrote in message ... Jim Donohue wrote: Anyone who has been on a boat knows that a GPS *DOES NOT* for all practical purposes work all of the time. I've had a GPS fail several times, I've seen charting inaccuracies a number of times. Similar things have happened to almost every cruiser I know. You lead an unlucky life. I have never seen a significant outage of the GPS. I follow the tech literature on the subject. Aside from deliberate military actions the outages are very few, far between, and limited in time duration. As I said I have never seen one. You mean, other that the outages that have happened, there have been none? I'll admit the system has been pretty stable but individual satellites are taken down which causes minor hiccups. Several weeks ago, my wife's car GPS was off by a quarter mile for about 5 minutes - I have no idea what the cause was, but it could have been a problem on a boat. It is of course possible that you have a source of interference on your boat. That does happen. It is one of the reasons that multiple GPSs are sensible. Different devices have different weaknesses. I am sure there are also some specific locations that have a multi-path problem. Again though few and far between. GPS ain't perfect but it is very close. Done with redundant instruments on the open sea it is, for all practical purposes, perfect. The problem that has bit me a few times is that I use a handheld which is connected to its cable every time I use the boat. If the power connection isn't solid, it can fall back to battery power, and then shut off a few hours later. I keep spare cables and batteries, but when it happens, I'm down for a few minutes. And although I often have a chart cartridge, I've found occasional "dropouts" in the coverage - rather disconcerting when you're in a tricky section of the ICW and the chart screen suddenly goes blank. On my previous boat (Nonsuch 30) I would lose signal sometimes. I assumed it was from the wishbone boom, but others claimed the antennae was too low and the signal was blocked by crew members; perhaps both causes were factors. I've never been hit by lightning, by I know many others that have, and the GPS is frequently a victim. I've also heard of GPS's damaged by power spikes. Actually, the first time I took a GPS on a trip its menu button was damaged so it was virtually useless. Having a spare GPS, and batteries, cables, etc. on board is useful and prudent, but it doesn't help when you lose the primary in a tricky situation. While these problems are infrequent, and often "operator error" it does not mean they don't happen. And having a strategy to cope, such as carrying a redundant GPS doesn't help you for the time it takes find it and fire it up. The present cruiser population is certainly and effectively completely dependent on GPS for off shore navigation. At this point I don't think there are many exceptions left. I have not come across a report of a significant problem with that in a long time. What's your point? The vast majority of boaters don't go offshore. And obviously, piloting techniques are not commonly used off shore. You keep trying to equate piloting with celestial; they're are not the same thing. Charting inaccuracies are chart problems very close to completely. Without gps they are hard to detect. The ones on the West coast of Mexico however are detectible with a good LORAN. Without GPS the charting inaccuracies would not be as important. As I mentioned before, I watched a trawler run aground because they trusted the GPS and didn't watch the depth. None of these incidents were a major problem for me because I was using other techniques and was able to recognize the situation and compensate. The issue here is not which technique is the most accurate, or which should be used to the exclusion of the other. Continuing to cast it in these terms make you look like a jaxian fool. One uses all reasonable methods available. The first and primary of these is GPS. Your inablity to understand this simple statement is almost jaxian. The question isn't what should be used first; the question is what should be taught first. Your inability to understand that is beyond jaxian. Teaching someone GPS before basic piloting is like teaching children how to use a calculator before teaching them the addition table. The issue is that you claimed it was foolish to teach someone basic piloting, even when the person was eager to learn. This attitude marks you as a complete fool, Jim. I hope I never meet one of your students on the water. No my argument was that basic navigation...not piloting...was better taught with GPS as the primary technique. It was in response to an individual teaching basic navigation with electronic aids removed. Actually, the case was that someone was learning how to do LOP's and DR and wasn't interested in LORAN. You called this "utter nonsense." I call your attitude "sheer stupidity." It is even possible that the individual involved and I would end at the same end point. Just different routings. It is remotely possible, but someone who learns how to use a GPS first is rather unlikely to then learn basic piloting. And this is the essential point of my argument. Anyone can teach them self how to use a GPS; learning piloting usually takes instruction and practice. If I only have a student for a few hours, I'd rather spend time on something that's harder to learn, and just as important. Most of the concepts of piloting relate to GPS usage, so nothing is wasted. And you again utterly misstate my position. GPS is the first skill taught...it should be the centerpiece of the navigation system. Then others. Certainly even the dullest of students can learn to check a chart position via eyeball or radar. Are you daft, man? Are you claiming now that piloting need not be taught because "even the dullest" can do it without training? And radar too? Bizarre, considering you've confessed to have weak radar skills! Listen carefully. Pilotage is important. One teaches navigation with the GPS first. One person might do that, the rest of us will teach properly, thank you. The first portion of that instruction is the use of charts. agreed. A current student however should learn with the GPS positon centric techniques rather than the LOP techniques of conventional DR. DR doesn't involve LOPs. Its clear your understanding in this area is weak. Yes eventually these get taught also...but secondary to what is the real world. Eventually? Yea, right. You asserted that learning LOP's and DR was "utter nonsense." I think no one should be trusted with a GPS until the learn these basics. Uhhh where did it state that learning LOPs and DR was "utter nonsense"? I think I made such a comment about teaching a student navigation with such techniques emphasized to the exclusion of electronic navigation. Still do. Perhaps you should re-read your fist post in this thread. Dave said his daughter was enjoying learning LOP's and DR, and wasn't interested in the Loran. Your response was "Ohh stop...what utter nonsense." You went on to spew more silliness which only served to make you feel important and make everyone else think you're a fool. Nowhere was it mentioned that Dave's daughter would not go on to learn other techniques, or that she was even destined to be a boat's navigator. It was only stated that she enjoyed learning basic piloting. Frankly criticizing anyone for wanting to learn almost anything is a mark of a very small mind. You correctly point out that it will be difficult to teach DR/LOP after one learns electronic navigation. That is because it is difficult to convince the student that sufficient value exists in such techniques. You deal with this value problem by teaching DR/LOP first. There's a bit more to it, but OK ... I claim simple that this in no way prevents the knowledge of DR/LOP going away real fast. I think we need to develop that set of DR/LOP skills that will actually stick after electronic navigation is learned. If we can't develop such a set and convince the newby of value then the outcome is the same. The way to do this is to actively practice "manual techniques" even while using a GPS. I've never known someone who learned GPS first who did this. However, once you have actually navigated by LOP's, or following depth contours, or watching "danger bearings," it starts to become automatic. When I see a buoy line up with a point of land, I mentally follow the line on the chart and check the depth I should be in. It only takes a second, but would someone who had never done that "for real" bother to do it? I stress the electronic navigation first because I think it more important they do that well than that they master an initial set of techniques they will abandon upon learning the electronic version. First good at the primary system then good at the secondaries. Too bad the world doesn't work this way. We could teach calculators in the third grade because the kids could be trusted to learn long division later. I introduce VOR/DME and RDF merely to demonstrate that we really don't propose to teach all available navigation techniques...only those that we believe useful and reasonable. There are lots of techniques that are arcane or obsolete. They may be of interest to the advanced navigator or hobbies, but they are in a different category from piloting, especially when the equipment isn't often carried on board. The NTSB study blamed several "probable causes:" over reliance on GPS, and lack of training of the officers, and the failure to recognize the problem from other cues. This is a perfect example of problem with your approach. Claiming that your strategy works, but in this case they were incompetent is foolish. http://www.ntsb.gov/publictn/1997/MAR9701.pdf I am reasonably familiar with the report. Find for me any mention of over reliance on GPS. It does find fault with over reliance on the automatic features of integrated bridge systems. Calling it a "system" was a euphemism. It was a GPS attached to an autopilot. They ignored the depth sounder, the radar, and visual cues. Actually, the same thing could have happened to most anyone with an Autohelm and a Garmin, except the the Autohelm (now Raymarine) gives a better indication of faulty input. It also discusses flaws in the design of such systems. I agree that total reliance on a single GPS is not wise. I generally run three...and two are active in the process to try to avoid the entry errors that I believe are the worst problems with GPS navigation. When the europeans get their system operative or the Russians complete theirs I will almost certainly run one GPS off another system. I will also use other inputs like depthsounders and radar to help prevent errors. So you turn on 3 gps's for a day sail? I think you'd be better served by brushing up on more basic skills. |
Roger Long wrote:
I'm kind of surprised that worked. VOR's are so hard ... my bad, it was an ADF device for marine purposes. that's what I get for posting while still asleep :-) |
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