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#21
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Questions on Radar
On Thu, 18 Dec 2003 17:40:10 -0800, "Lloyd Sumpter"
wrote: Hi, Considering buying a radar, so I have a few questions: 1. On a sailboat, where do you put the display? I rarely steer from behind the wheel, mainly by sitting on one of the gunwales beside the wheel, or sometimes by Otto while hiding from the rain under the dodger (hence the name... ). When I installed the RL70CRC on Geoff's Endeavour 35, I mounted it on a swivel mount he bought from Waste Marine made of anodized aluminum so it could be swung around to the port side of the wheel, to view from behind, or swung out over the cockpit table to view from either of the lazarette seats. It was mounted with U clamps to the pedestal vertical bars. Be sure to leave plenty of cable length so you don't pull on the plugs. The only problem was the mount's locking knob under the "table" of it came loose too easily. We broke the knob trying to make it hold in heavy seas. It ended up lashed down in heavy weather offshore to keep it from banging around. 2. Realistically, how far do you set the max range? I'm seeing that unless I mount the antenna up the mast, I'm not gonna get more than maybe 10 miles range no matter what unit I buy. Then again, if I see a freighter steaming at 30 knots, 10 miles away, I still have 20 minutes to do something. Is a 20-mile range worth getting? We use the 2KW radome to hold down the load on the house batteries for long periods. When we moved it from the stern mounting pole, on the Endeavour, about 20' off the water, to the Amel Sharki 41's mizzenmast it moved up to double its original altitude. This reduces our MINIMUM usable range, something I consider far more important than seeing that freighter 30 miles away, especially when you are in pea soup fog. I want to see that bouy on the screen until I can hear it clanking around on its chain. At 40', I lose the bouy about 200 yards away, which I guess is still OK. Don't go way up as you'll shoot right over the close-in targets you're about to run over. But, don't go too low, either, because you'll lose targets when you are in the trough between swells higher than the radome. On a sailboat, 2KW is plenty of power. Three mile range is plenty of time to take evasive action when you're plodding along at sailboat speeds. It also lets you see all the targets and use the MARPA to track them, if you got it. MARPA works great for us. Once assigned a target, MARPA watches him for us, alarming if he's going to get in the way. I like the way it shows his course and speed over time, much like a military radar I'm used to. 2KW from 40' up can see the shore targets as far as you can see on a clear day, but in the fog. Of course, with WAAS-GPS, using the radar to find your position becomes pretty moot. I want to see that idiot in the center console fishing boat and what he's doing, myself. 3. Do you trust yours enough to use it instead of a "watch" (ie watch the radar screen instead of where you're going)? Trying to decide if getting a radar will increase my cruising time significantly (ie more confidence in running at night) No, it doesn't. Case in point is on my last trip from Florida on the Endeavour 35 with one of the neighbors. We had used the radar all night in pitch dark, under sail, about 80W off the GA coast, heading the boat home to Charleston after Geoff left it in Daytona Beach. The sun had risen and there were no targets on a beautiful morning in a relatively smooth sea with little swell. We were only making about 3 knots, but didn't really care. No schedule is great. Breakfast was on the cockpit table and we had just set down to eat. I looked up at Lloyd to answer a question and this HUGE WOODEN SPOOL cable reel was floating about 30 yards off the port beam! That thing must have been 30 feet across and 15 feet wide! It was HUGE! I rushed to the radar screen as it went by and set the range to 1/8th mile to see why it hadn't alarmed. There was NO RETURN WHATSOEVER from this target from 30 yards off the port beam until I lost sight of it behind us....not a single blip. There just wasn't enough metal inside the wooden reel to show up on the radar. While continuing breakfast, we both mused over the possibilities of hitting that reel at 8 knots during the night after the moon went down and you couldn't see past the nav lights on the bow. I got goosebumps. Radar can't see everything. It can only see radio reflections, not wooden or absorptive obstructions.....like that thousand-pound cable reel just floating around out there... 4. I see a "guard zone alarm" but no "constant-bearing alarm". Why not? wouldn't a constant-bearing alarm be far more useful (and not that hard to implement)? The guard zone alarms you to targets popping up in the guard zone. MARPA, or whatever they call it on the other companies, tracks the target for you, giving you course, speed, and watching to see it isn't on a collision course with you. But, you must assign the target on MARPA. It doesn't assign it automatically. If you think radar is going to eliminate watches, you're barking up the wrong tree. It's an AID, not a watch stander. 5. I'm looking at the Furuno 1623 or 1712, or the JRC 1000. I have a Furuno GP-31 GPS and I'm impressed by the quality (also, probably 90% of commercial boats around here have Furuno radars). Any comments? Buy what you can get SERVICED, LOCALLY. I suspect they're all running Furuno because someone is there to fix them and sells them locally. Don't cheap-out or you'll regret it later. The most useful electronics on Lionheart is the RL70CRC Plus Color radar-chartplotter which overlays the radar right on the chart for us. It matches the GPS position, already plotted for us on the chart display to the returns the radar is seeing any time we're near land or known objects. With it I can even tell you which side of the channel that fisherman is anchored to because I can see him ON THE CHART. As soon as it was installed, everyone quit using the GPS chart plotter in the Garmin 185. Geoff built a nice fiberglass console to mount this most-useful display right in front of the helmsman's nose where the compass used to be. It's THAT useful....(c; 6. Is it worth while to mount the antenna up the mast, or should I use a "dedicated" mast at the transom? Been on both, and it's a real tossup. The Endeavour was mounted on a tilting mast on the transom. The tilt mechanism was useless as it was hard to reach and hard to set. If you could pull a lanyard, instead of screwing thumbscrews around, it might have been useful. The 2KW radome antenna is a piece of circuit board with little antennas on it rotated by the same motor a cassette player in your car uses by a rubber belt. (I put a spare belt inside the radome before it was put on the mast, by the way.) This antenna has a very wide vertical beamwidth so it works fine even if heeled over 20 degrees. The new mounting is fixed on the mizzenmast at about 40'. It can pick up smaller targets further away, but loses them under the beam about 200 yards from the boat, where I used to see them down to the third finger pier from ours on the dock. I wouldn't go above 40' for fear of losing the close-in targets you're going to run into in the fog or dark. MAKE SURE ANYTHING IN THE WAY FORWARD of the radome is a long ways from the radome. Lionheart has a big in-mast furling monster mast. I can see targets disappearing at 000 relative, even though the masts are 25' apart. If it were closer, we'd have a large blind spot where it counts the most. That's all for now...dreaming on a dull winter's day... Go sailing with some various radars and play around with them before you decide. Larry Larry W4CSC NNNN |
#22
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Questions on Radar
"Lloyd Sumpter" wrote in
: 1. On a sailboat, where do you put the display? I have my display right at the wheel so that you have no problem seeing it from where you're steering. I have my chart plotter, a NorthStar 961, mounted right there too. I've never understood people who mount their radar by the nav station. Maybe a second head, but you need to be able to interpert all of the data being presented to you in one location. Maybe others can do this, but I want everything where I am using it. Here's a photo of the wheel, chart plotter and radar (lower left) http://www.geoffschultz.org/1999_Sailing/1999_01 _FtLauderdale_Captiva/990104_keylargo_marathon/imagepages/image5.htm And here's a photo of the display lit at night. http://www.geoffschultz.org/1998_Sai...h_Florida/Day_ 14/imagepages/image6.htm 2. Realistically, how far do you set the max range? I normally keep it on the 4 to 8 nm range. For weather tracking I bump it out to 12+ miles, which is about it's max range. 3. Do you trust yours enough to use it instead of a "watch" As virtually everyone has said, you need a pair of eyes. The watch is good to provide another set, but someone has to be watching and listening. 4. I see a "guard zone alarm" but no "constant-bearing alarm". Quite often when you're in seas or gusty conditions I find that the boat isn't tracking 100% on the same course (Perhaps an understatement). As a result, the bearing to the target is changing and needs a human interperation of what's going on. 6) Mounting I have a transom mounted radar pole. That works fine, but I'd rather have it up the mast and have it gimbled. -- Geoff Hi, Considering buying a radar, so I have a few questions: 1. On a sailboat, where do you put the display? I rarely steer from behind the wheel, mainly by sitting on one of the gunwales beside the wheel, or sometimes by Otto while hiding from the rain under the dodger (hence the name... ). 2. Realistically, how far do you set the max range? I'm seeing that unless I mount the antenna up the mast, I'm not gonna get more than maybe 10 miles range no matter what unit I buy. Then again, if I see a freighter steaming at 30 knots, 10 miles away, I still have 20 minutes to do something. Is a 20-mile range worth getting? 3. Do you trust yours enough to use it instead of a "watch" (ie watch the radar screen instead of where you're going)? Trying to decide if getting a radar will increase my cruising time significantly (ie more confidence in running at night) 4. I see a "guard zone alarm" but no "constant-bearing alarm". Why not? wouldn't a constant-bearing alarm be far more useful (and not that hard to implement)? 5. I'm looking at the Furuno 1623 or 1712, or the JRC 1000. I have a Furuno GP-31 GPS and I'm impressed by the quality (also, probably 90% of commercial boats around here have Furuno radars). Any comments? 6. Is it worth while to mount the antenna up the mast, or should I use a "dedicated" mast at the transom? That's all for now...dreaming on a dull winter's day... Lloyd Sumpter "Far Cove" Catalina 36 |
#23
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Questions on Radar
"Lloyd Sumpter" wrote in
: 1. On a sailboat, where do you put the display? I have my display right at the wheel so that you have no problem seeing it from where you're steering. I have my chart plotter, a NorthStar 961, mounted right there too. I've never understood people who mount their radar by the nav station. Maybe a second head, but you need to be able to interpert all of the data being presented to you in one location. Maybe others can do this, but I want everything where I am using it. Here's a photo of the wheel, chart plotter and radar (lower left) http://www.geoffschultz.org/1999_Sailing/1999_01 _FtLauderdale_Captiva/990104_keylargo_marathon/imagepages/image5.htm And here's a photo of the display lit at night. http://www.geoffschultz.org/1998_Sai...h_Florida/Day_ 14/imagepages/image6.htm 2. Realistically, how far do you set the max range? I normally keep it on the 4 to 8 nm range. For weather tracking I bump it out to 12+ miles, which is about it's max range. 3. Do you trust yours enough to use it instead of a "watch" As virtually everyone has said, you need a pair of eyes. The watch is good to provide another set, but someone has to be watching and listening. 4. I see a "guard zone alarm" but no "constant-bearing alarm". Quite often when you're in seas or gusty conditions I find that the boat isn't tracking 100% on the same course (Perhaps an understatement). As a result, the bearing to the target is changing and needs a human interperation of what's going on. 6) Mounting I have a transom mounted radar pole. That works fine, but I'd rather have it up the mast and have it gimbled. -- Geoff Hi, Considering buying a radar, so I have a few questions: 1. On a sailboat, where do you put the display? I rarely steer from behind the wheel, mainly by sitting on one of the gunwales beside the wheel, or sometimes by Otto while hiding from the rain under the dodger (hence the name... ). 2. Realistically, how far do you set the max range? I'm seeing that unless I mount the antenna up the mast, I'm not gonna get more than maybe 10 miles range no matter what unit I buy. Then again, if I see a freighter steaming at 30 knots, 10 miles away, I still have 20 minutes to do something. Is a 20-mile range worth getting? 3. Do you trust yours enough to use it instead of a "watch" (ie watch the radar screen instead of where you're going)? Trying to decide if getting a radar will increase my cruising time significantly (ie more confidence in running at night) 4. I see a "guard zone alarm" but no "constant-bearing alarm". Why not? wouldn't a constant-bearing alarm be far more useful (and not that hard to implement)? 5. I'm looking at the Furuno 1623 or 1712, or the JRC 1000. I have a Furuno GP-31 GPS and I'm impressed by the quality (also, probably 90% of commercial boats around here have Furuno radars). Any comments? 6. Is it worth while to mount the antenna up the mast, or should I use a "dedicated" mast at the transom? That's all for now...dreaming on a dull winter's day... Lloyd Sumpter "Far Cove" Catalina 36 |
#24
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Questions on Radar
On Thu, 18 Dec 2003 17:40:10 -0800, "Lloyd Sumpter"
wrote: Hi, Considering buying a radar, so I have a few questions: 1. On a sailboat, where do you put the display? I rarely steer from behind the wheel, mainly by sitting on one of the gunwales beside the wheel, or sometimes by Otto while hiding from the rain under the dodger (hence the name... ). 2. Realistically, how far do you set the max range? I'm seeing that unless I mount the antenna up the mast, I'm not gonna get more than maybe 10 miles range no matter what unit I buy. Then again, if I see a freighter steaming at 30 knots, 10 miles away, I still have 20 minutes to do something. Is a 20-mile range worth getting? 3. Do you trust yours enough to use it instead of a "watch" (ie watch the radar screen instead of where you're going)? Trying to decide if getting a radar will increase my cruising time significantly (ie more confidence in running at night) 4. I see a "guard zone alarm" but no "constant-bearing alarm". Why not? wouldn't a constant-bearing alarm be far more useful (and not that hard to implement)? What you need for this is a mode called "true motion". It requires a good electronic compass or gyro fed to the radar. The picture on the radar stays still and you move across the picture. When you reach the edge of the screen it resets you to the bottom of the screen with a new picture. Other boats also move across the picture on the screen. With this system you can put a cursor on another boat and your boat can yaw or move anywhere and the cursor will remain at the same azimuth that you set it at relative to your position. That will let you see if the other boat is on coarse to you. The MARPA systems in the small radars you have to manually acquire the targets. Most are limited to around 6 targets that they will track at one time. If you loose contact with a target for a time you have to reacquire it again. It can become a pain to use. It sounds like an ideal thing to have but in reality it is a lot of work to use. The true motion though is very useful. I have an older raytheon 21xx that has both in it. Regards Gary 5. I'm looking at the Furuno 1623 or 1712, or the JRC 1000. I have a Furuno GP-31 GPS and I'm impressed by the quality (also, probably 90% of commercial boats around here have Furuno radars). Any comments? 6. Is it worth while to mount the antenna up the mast, or should I use a "dedicated" mast at the transom? That's all for now...dreaming on a dull winter's day... Lloyd Sumpter "Far Cove" Catalina 36 |
#25
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Questions on Radar
On Thu, 18 Dec 2003 17:40:10 -0800, "Lloyd Sumpter"
wrote: Hi, Considering buying a radar, so I have a few questions: 1. On a sailboat, where do you put the display? I rarely steer from behind the wheel, mainly by sitting on one of the gunwales beside the wheel, or sometimes by Otto while hiding from the rain under the dodger (hence the name... ). 2. Realistically, how far do you set the max range? I'm seeing that unless I mount the antenna up the mast, I'm not gonna get more than maybe 10 miles range no matter what unit I buy. Then again, if I see a freighter steaming at 30 knots, 10 miles away, I still have 20 minutes to do something. Is a 20-mile range worth getting? 3. Do you trust yours enough to use it instead of a "watch" (ie watch the radar screen instead of where you're going)? Trying to decide if getting a radar will increase my cruising time significantly (ie more confidence in running at night) 4. I see a "guard zone alarm" but no "constant-bearing alarm". Why not? wouldn't a constant-bearing alarm be far more useful (and not that hard to implement)? What you need for this is a mode called "true motion". It requires a good electronic compass or gyro fed to the radar. The picture on the radar stays still and you move across the picture. When you reach the edge of the screen it resets you to the bottom of the screen with a new picture. Other boats also move across the picture on the screen. With this system you can put a cursor on another boat and your boat can yaw or move anywhere and the cursor will remain at the same azimuth that you set it at relative to your position. That will let you see if the other boat is on coarse to you. The MARPA systems in the small radars you have to manually acquire the targets. Most are limited to around 6 targets that they will track at one time. If you loose contact with a target for a time you have to reacquire it again. It can become a pain to use. It sounds like an ideal thing to have but in reality it is a lot of work to use. The true motion though is very useful. I have an older raytheon 21xx that has both in it. Regards Gary 5. I'm looking at the Furuno 1623 or 1712, or the JRC 1000. I have a Furuno GP-31 GPS and I'm impressed by the quality (also, probably 90% of commercial boats around here have Furuno radars). Any comments? 6. Is it worth while to mount the antenna up the mast, or should I use a "dedicated" mast at the transom? That's all for now...dreaming on a dull winter's day... Lloyd Sumpter "Far Cove" Catalina 36 |
#26
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Questions on Radar
On Thu, 18 Dec 2003 17:40:10 +0000, Lloyd Sumpter wrote:
Hi, Considering buying a radar, so I have a few questions: Wow - thanks for all the Great Answers! Lots of things I hadn't considered, like losing close-in target if the antenna is too high. As for display mounting, the reason I asked about watches is that the "obvious" place would be the nav station, but I can't see where I'm going from there, so it would only be useful if I was using the radar as a closed-cct TV. Sounds like that's not an option, so scratch the nav station as a possible mounting place. I currently use a swing-out arm for my sounder, and it works well, but blocks the companionway - something I'd rather not do for long periods. I'll consider it, but I think I'll go with another option. That leaves on the "deck" under the dodger (where I put my "convertable" speakers), or on the binnacle. Binnacle would be good for when I'm at the wheel (with a swivel so I can see it when I'm beside the wheel), but I just don't like clutter on my binnacle: I like to see my compass, and I sometimes lean against it and steer with the wheel behind me. OTOH, the dodger option would be kinda far away when I'm at the wheel, but good when I'm ducking under the dodger ("DUCK DODGER - In The 24 1/2 Century!" - thank you, Chuck Jones!) But in either case, I'd be removing the display when the boat is docked. How easy is this, especially the connectors? How well would the connectors handle being out in the weather - is there some kind of protective cover for them? The dodger option might allow me to snake the cables up from below, but they might get in the way ("Sailor Strangled By Radar Cable: Film at 11.."). One thing I noticed about the Furuno 1721: it had a "secondary display" option - is this as good as it sounds? Also, one feature the 1721 had is that on "standby" it displays the nav data it gets via NMEA from the GPS - that also sounds like a Good Feature, and make the binnacle mount a good option (since the GPS would be right below it if it was under the dodger). Again, thanks for all the help! Lloyd Sumpter "Far Cove" Catalina 36 |
#27
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Questions on Radar
On Thu, 18 Dec 2003 17:40:10 +0000, Lloyd Sumpter wrote:
Hi, Considering buying a radar, so I have a few questions: Wow - thanks for all the Great Answers! Lots of things I hadn't considered, like losing close-in target if the antenna is too high. As for display mounting, the reason I asked about watches is that the "obvious" place would be the nav station, but I can't see where I'm going from there, so it would only be useful if I was using the radar as a closed-cct TV. Sounds like that's not an option, so scratch the nav station as a possible mounting place. I currently use a swing-out arm for my sounder, and it works well, but blocks the companionway - something I'd rather not do for long periods. I'll consider it, but I think I'll go with another option. That leaves on the "deck" under the dodger (where I put my "convertable" speakers), or on the binnacle. Binnacle would be good for when I'm at the wheel (with a swivel so I can see it when I'm beside the wheel), but I just don't like clutter on my binnacle: I like to see my compass, and I sometimes lean against it and steer with the wheel behind me. OTOH, the dodger option would be kinda far away when I'm at the wheel, but good when I'm ducking under the dodger ("DUCK DODGER - In The 24 1/2 Century!" - thank you, Chuck Jones!) But in either case, I'd be removing the display when the boat is docked. How easy is this, especially the connectors? How well would the connectors handle being out in the weather - is there some kind of protective cover for them? The dodger option might allow me to snake the cables up from below, but they might get in the way ("Sailor Strangled By Radar Cable: Film at 11.."). One thing I noticed about the Furuno 1721: it had a "secondary display" option - is this as good as it sounds? Also, one feature the 1721 had is that on "standby" it displays the nav data it gets via NMEA from the GPS - that also sounds like a Good Feature, and make the binnacle mount a good option (since the GPS would be right below it if it was under the dodger). Again, thanks for all the help! Lloyd Sumpter "Far Cove" Catalina 36 |
#28
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Questions on Radar
Some comments on a few of the points made:
1. Range - Use the GREATEST range that shows a solid picture for your area. If you stay on the 0.25 and 0.5 mile scales for normal operation, you are highly limiting the overall value of the radar. Think of it like driving your car down the freeway, always looking as far ahead as possible and then looking in close as you encounter traffic, etc. Admittedly, the vessel targets will appear smaller, but you can always scan down as they approach. 2. True motion - Very few ships use or even have this choice, nowadays (most hated the screen resetting as you approached the edge). What is normally used ( and available to some small boaters) is "North UP" or gyro stabilized, which is frequently referred to, incorrectly, as true motion. This means you stay in the center of the screen, but your heading flasher moves, so direct bearings can easily be taken. I'd call it the best of both worlds. 3. ARPA - if you can get this and use it, do so. Even on ships, the norm is to leave the auto designate off (this is changing) and manually acquire targets. Once you learn how to use it, it can really simplify your collision avoidance options. otn |
#29
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Questions on Radar
Some comments on a few of the points made:
1. Range - Use the GREATEST range that shows a solid picture for your area. If you stay on the 0.25 and 0.5 mile scales for normal operation, you are highly limiting the overall value of the radar. Think of it like driving your car down the freeway, always looking as far ahead as possible and then looking in close as you encounter traffic, etc. Admittedly, the vessel targets will appear smaller, but you can always scan down as they approach. 2. True motion - Very few ships use or even have this choice, nowadays (most hated the screen resetting as you approached the edge). What is normally used ( and available to some small boaters) is "North UP" or gyro stabilized, which is frequently referred to, incorrectly, as true motion. This means you stay in the center of the screen, but your heading flasher moves, so direct bearings can easily be taken. I'd call it the best of both worlds. 3. ARPA - if you can get this and use it, do so. Even on ships, the norm is to leave the auto designate off (this is changing) and manually acquire targets. Once you learn how to use it, it can really simplify your collision avoidance options. otn |
#30
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Questions on Radar
Lloyd Sumpter wrote:
.."obvious" place would be the nav station, but... Your conclusion that the nav station i less than optimal is correct. A friend of mine has it mounted there on his Valiant and having played "radar officer" shouting instructions up to him at the helm at we motyored under the Golden Gate dodging freighters in heavy fog ("Come left another 15 degrees, it looks like the current is setting us toward the point!"), you really don't want to go there. I currently use a swing-out arm for my sounder, and it works well, but blocks the companionway - something I'd rather not do for long periods. We've actually got two swing out arms. One for the GPS/fish finder and one for the radar. The truth of the matter is that we actually use the radar infrequently enough that this is really not a problem for us. But in either case, I'd be removing the display when the boat is docked. How easy is this, especially the connectors? Easy to do, but I'd be concerned about two things: #1 The connectors eventually wearing out or bending a pin and #2 accidentaly damaging the unit by dropping it or banging ito something as I'm carrying it and the boat lurches or something. Take care - Dan -- Dan Best - (707) 431-1662, Healdsburg, CA 95448 B-2/75 1977-1979 Tayana 37 #192, "Tricia Jean" http://rangerbest.home.comcast.net/TriciaJean.JPG |
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