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October 26 - What A Drag!
I'm a bit surprised that after the first drag, you didn't set an anchor
watch for the night. I think you are using up your luck here, Skip. -paul |
October 26 - What A Drag!
October 26 - What A Drag!
When we left you, I promised to tell you of more that I learned in Oxford, MD. Boy, Howdy, as they say in the south where I used to live... We're in Oxford, a charming (are all Chesapeake area towns like this??) very small city on the Tred Avon River. It's home to an amazing wooden boat builder who uses kevlar in his construction, a couple of museums, a major Hinkley shop, and the usual assortment of very nice people, dogs, birds, squirrels and other fauna. Just tonight, a goose swam up to our platform and begged; we fed her a piece of bread which she daintily took, piece by piece, from our hands. On our trip into town earlier, we encountered yet another very friendly dog walking his owner, who was also friendly, so we chatted both up for a while before heading in for the touristy stuff. That was today, what we expect, if the weather holds, to be our last day here. I'd slept in, dramatically for me, for reasons we'll discuss anon, but it's been really nasty weather for the last couple of days. To bring you up to date on our education, I have to back up a couple of days... As usual, the ladies slept in yesterday, and so the laundry and shopping got off to a late start. Worse, the weather was really stinky, with pretty constant rain, and going off in the dinghy wasn't much fun to consider. However, it looked like it was clearing up, so Lydia and her Mom went off to load the machines at Mears. Lydia was going to bring her mom back and then go for a long walk but as soon as they got there, it commenced raining even harder than before. So, they stayed and instead took advantage of the showers there and chatted up the locals. One of them, Pete, was considering the liveaboard and full-time travel routine that we're doing, and asked to join us for dinner, providing the ride to Latitude 38. We'd noted that the other boats in the anchorage had left overnight. Pete said that the power boat anchored in front of Mears had dragged all the way across the channel in the storm in the morning, coming to rest against a marker post. That would prove very interesting to us later, but we felt smug on our 55 pound Delta and all chain rode, still stuck where we started. Anyway, laundry finished, all showered up, they finally returned in a lull in the rain. Because it was so nasty, and also, by that time, so late, we elected to stay another day, having still not gotten in to do our exploring. After all, it seems a bit much to come all this way only to go to dinner. We dinghied in to the landing and Pete picked us up, heading off to another memorable dinner at Latitude 38. Wednesday night is Prime Rib night, and the place is packed. However, Wendy, the owner, recognizes us immediately, and after asking how we got there (she expected to come pick us up), got our table ready quickly. Pete and I talked at length about all the realities and challenges of full-time cruising, but, even if he keeps his Freedom 33 (he thinks it might be too small) to do that, he could do it. He's a double retiree, Army and teaching, and has the means to cut the cord. So, all that we'd been through was very interesting to him, and we had a lovely time together as he picked our brains. By the time we returned to the dinghy, the weather had deteriorated, not only raining but blowing rather energetically. We'd found good holding, though, and our 55# Delta has been criticized as too big for the boat as it was, so we felt reasonably comfortable with our position. The first thing we learned was that we likely had fouled our anchor in all the changes of direction. In the morning, we'd been facing, with relatively high winds, all 4 points of the compass, but eventually straightened out from what had been a strong wind South to land in a relatively northerly position. I say "likely" because I couldn't believe that big mother of an anchor and the long all-chain we'd put out, after being firmly set, could slide. Wishful thinking. We were sliding, and in danger of winding up in the docks of where we landed our dinghy. Hurry and start the engine, pull up the anchor while motoring into the wind, but still get blown on to, at the very end of the boat - our arch - a marker pole. No big deal, as we get off, and then go for a re-anchor. Once again, we stick it firmly, and let out lots of scope. As the winds are forecast to remain very consistent, after watching the GPS like a hawk for about an hour, at close to 1AM I go to bed as the winds outside howl. A little after 3AM, I feel something's not quite right. We've got more heel than would be likely with the level of wind we've got, and even more strangely, it seems to be coming from more abeam than would be the case from just sailing around at anchor. So, I get up to have a look. EEEK! There's a boat behind us, in a dock, not 15 feet from our stern. Off to our port, about 100' away, there's a seawall. The wind is exactly on our beam, and blowing pretty good. Worse, I don't see anything I've ever seen, let alone recognize nor know where I am. However, the good news, if you can call it that, is that we seem to be aground, and appear not to be in any danger of running into the boat behind us, nor the seawall. I grab a boathook to confirm that we are, in fact, aground. Our chain is stretched out nearly perpendicular to the boat. Obviously, we've dragged, went aground, and the bow swung around until it stopped, I got out the searchlight and tried to find any familiar landmark. I couldn't. I didn't recognize anything. However, I could see channel markers, much higher in number than I recalled, so at least we could find our way out, if we could get off the ground. I turned on the inverter, fired up the laptop, booted the Cap'n, and saw that we were at high tide. Great! Just like in St. Michaels, if we don't get off immediately, we're not going to, for a while. However, this time, we're reacting in realtime, rather than later, and it makes a difference. I got Lydia up, raised the front window of the dodger so we could see against the glare I was creating, put on our Marriage Saver headsets so that we could communicate even in the howling wind, with me on the bow and her driving, and commenced getting off. Fortunately, our anchor, while it had dragged all that way, was still stuck, so my kedging got the nose around, and as Lydia applied full starboard and throttle, she stood up and we were off. We picked our way back to where we'd been, as, now that we were the only boat in the anchorage, there was plenty of room. Later, in the daylight, I was able to see that we'd dragged probably a quarter mile, managing not to hit anything along the way to our sandy/muddy resting place. WHEW! (Back to the education.) I also learned that I was very annoyed that our already oversized anchor should have dragged. However, we also have a second, even bigger anchor up front. The 75# CQR, with, also, all chain at this length, was deployed for the first time, following a longer-than-normal rode on the Delta. It hooks, and I let out about a 7-1 scope on it. The two hold, with about an initial 30* angle between them. However, twice burned, infinitely shy. All this has taken about an hour and a half, and it's about 4:30. I send Lydia to bed and take up anchor watch. I look at the GPS in thousandths of a mile. Each thousandth represents about 5 feet, and the boat's swinging. Initially, it looks like it must be dragging again, but I watch it like a hawk. It varies enough that I figure the only way I'm going to have a comfort level about whether it's actually dragging is to log it. As some of the N/S variances were as much as 10, that would mean 50 feet or so. Not a comfortable feeling, especially as it's happening over a relatively short time frame. But, I can't really see any apparent movement with the circle-scope trying to do mental calculations about what that would mean in N/S and E/W movement. So, every minute, beginning at 5AM, I log the thousandths of north and west. After about the first hour, I also log the wind at the time, in order to calculate the swing and change in location. More education, I think I learn that I can't fully trust the GPS, as it seems that we've actually moved, based on a landmark reference, but the GPS doesn't track that. However, I'm able to see that our noted position has recurred in several cases throughout the total of logged minutes, so we're revisiting the same spot(s). Whether or not the "automatic rough" (the syndrome that has pilots hearing something wrong with the engine when visibility declines making them not have ready emergency landing places visible - but the engine's actually just as it always is) was responsible or it really was slightly dragging, if we were going back over the same spots we'd been in over that time, we couldn't be doing too badly. None the less, as no further apparent (negative) movement occurs, after 2 hours, I go to every 5 minute logging, and finally, at 8AM, when it's light again, conclude that we're fully hooked, and aren't doing anything more than swinging on our two anchors. Lesson learned is that our two anchors will hold when one oversized one, on excess scope, in good holding, apparently, won't. Another lesson learned is that were this a hurricane, we'd need a great deal more holding than we had put out last night, as I don't have confidence that our second anchor would have made the sufficient difference. I'll save our hurricane prep for another time, but it's enough to say that we have a great deal more holding and tying aboard than we've used here, so we think we'll be ok. Of course, the main thing will be to not be where there's a hurricane! So, in the end, I slept until 2, unheard of for me, and we went to town in lots of wind, but still relatively warm. Our return was dry, if a bit spitty with rain, and lots of wind, and we settled in to an early dinner and movie in the still-warm cabin made even toastier for the cooking. We've stayed fixed in exactly (swinging aside, of course) the same position throughout the 20-25knot winds all day (and for that matter, since before 5AM), so we're relatively comfortable that we'll still be here in the morning. Winds are forecast for 15knots east all day for our run to Solomons, where we expect to anchor in Back Creek. We'll be there for several days as we pick up various shipments sent to us, and try to enjoy the area with a little less drama than here! Postscript to that is the weather deteriorated to the point that not only would it be not much fun out there, but vis would decline in the afternoon. This morning, as I type, we're actively thinking in terms of going to Cambridge, with hopes that we'll be in graduate level studies there, rather than the painful underclassmen studies we're enduring here :{)) Stay tuned for further adventures. L8R Skip Morgan 461 #2 SV Flying Pig KI4MPC See our galleries at www.justpickone.org/skip/gallery ! Follow us at http://groups.google.com/group/flyingpiglog and/or http://groups.yahoo.com/group/TheFlyingPigLog "You are never given a wish without also being given the power to make it come true. You may have to work for it however." (and) "There is no such thing as a problem without a gift for you in its hands. You seek problems because you need their gifts." (Richard Bach, in The Reluctant Messiah) |
October 26 - What A Drag!
"Skip Gundlach" wrote in message ups.com... October 26 - What A Drag! snip... Did you mention an alarm on your GPS to sound if you drag a specified distance? |
October 26 - What A Drag!
On Fri, 26 Oct 2007 13:32:35 -0000, Skip Gundlach
wrote: Winds are forecast for 15knots east all day for our run to Solomons, where we expect to anchor in Back Creek. We'll be there for several days as we pick up various shipments sent to us, and try to enjoy the area with a little less drama than here! Be advised that the holding in Solomons is marginal also. It is one of the few places where our 120 pound Spade has not gotten a firm bite on the first try. The bottom is soft, silty mud with shells mixed in, not a good combination. Probably the best anchor for conditions like that is something with lots of fluke area, perhaps a large, oversized Fortress. Since they can be dissassembled, it is not that difficult to carry around a big one for "special" conditions. Something like their FX-85 would give you a great deal of holding power and only weighs 21 pounds. http://www.fortressanchors.com/fortr...hor_guide.html http://www.fortressanchors.com/safe_anchoring.html |
October 26 - What A Drag!
On Oct 26, 10:05 am, Wayne.B wrote:
On Fri, 26 Oct 2007 13:32:35 -0000, Skip Gundlach Since they can be dissassembled, it is not that difficult to carry around a big one for "special" conditions. Something like their FX-85 would give you a great deal of holding power and only weighs 21 pounds. Correction: FX-37 is 21 lbs, the FX-85 is 47lbs |
October 26 - What A Drag!
Wayne.B wrote:
On Fri, 26 Oct 2007 13:32:35 -0000, Skip Gundlach wrote: Winds are forecast for 15knots east all day for our run to Solomons, where we expect to anchor in Back Creek. We'll be there for several days as we pick up various shipments sent to us, and try to enjoy the area with a little less drama than here! Be advised that the holding in Solomons is marginal also. It is one of the few places where our 120 pound Spade has not gotten a firm bite on the first try. The bottom is soft, silty mud with shells mixed We anchored off Oxford (between the point and the ferry dock) in 2000and had no trouble with the holding although Bob had to reset the anchor once. At the time I wrote: !Tried to find the place in Town Creek, but there were 2 boats there already. ! !Went back out near the ferry dock and anchored. It took Bob two tries to get the anchor set. !Ernie came and rafted with us on our anchor (50 lb Max anchor with 125 feet of 5/16ths chain). Ernie called the restaurant he was going to take us to (Latitude 38) and then we each took our own dink and tied to the other side of the ferry dock. The restaurant sent someone to pick us up and take us to dinner. !This is a very fancy restaurant with fancy dishes and fancy prices. I took part of my steak home with me Alice had quail, and Bob had a scallops. Afterwards, we went back to our boats and had a nice chat. !In the morning, Ernie came over to our boat, and then I went over to his to show him how to use electronic charting software, but it is different from mine. I think he got cold feet and decided to figure it out himself after I said that I found out how to do it myself by "keep on trying until it either worked or broke". !Bob was concerned that we were dragging, because we had 2 heavy boats on one anchor. I thought that "Another Day" a motor boat that was anchored near us was dragging. We were in the same relation to the little orange and white buoy near the ferry dock that we had been. Bob and Ernie said he couldn't be dragging toward his anchor. Bob took in 50 feet of chain. ! !Eventually the guy on Another Day came out and looked at his anchor, but he didn't do anything about it. Bob and Ernie eventually admitted that I was right and he was dragging, but since we wanted to get to the South River that afternoon, and Another Day was getting too close for comfort, we unrafted about 9:50 and Ernie sped off. The anchor was up by 10:15. The next time we came to Oxford on that same 2000 trip (August) we docked at Mears Boatyard. !We walked over to the Chatterbox Cafe for lunch, and saw Jim and Pat working on their boat at Oxford boatyard and said we'd be back after lunch. One of the reasons we came back to Oxford was to visit with them - they were out of town when we were here before. ! !A big bowl (which they called a cup) of gazpacho was $4.50, and we each also had a chicken salad sandwich (had to eat with a fork) was $3.95. Very good and satisfying. ! !We walked around to the Oxford Boatyard and saw Jim and Pat's boat (they've completely torn out the interior - the exterior looks beautiful), and then it looked like rain, so while they stowed their tools,... !.. we walked back to our boat. It started to rain. Bob walked quickly back to our boat, and was able to close the ports and hatches that we'd left open before things got too wet, and put down the side curtains. ! !He got a little wet, but I (going more slowly) got absolutely soaked to the skin - it rained so hard I couldn't see very well because of the rain on my glasses. After I got to the boat, I stripped all my clothes off in the cockpit - the curtains were too steamed up for anyone to see me, and I didn't want to drip in the cabin any more than necessary. We actually hadn't needed to do a wash, but we did need to get all that wet stuff dry. ! !A big Island Packet named ExFed (painted in FedEx colors) had been put at the other end of our side of D dock. Jim and Pat (using trash bags as raincoats) came over to our boat and we visited while it gradually cleared a little. After they came aboard the marina guy put an Jeaneau in between ExFed and us. Jim asked if I didn't want to go forward and fend them off our boat and I said I thought our anchors would do just fine. No one would want their boat in contact with our ugly pointy anchors (one a Max and one a CQR). ! !They put a BIG Hattaras named Prima Donna on the T end of D dock. Their bow stuck out a little past our stern. They had a motor scooter aboard we found out later. ! !While Bob attempted the laundry, I used the pay phone (none of the portables worked) to download pocketmail. The pay phone was under the steps, right where the rain poured down on it. Everything there was wet and it was almost impossible to keep to receiver and the pocketmail dry even when I put it inside my raincoat. ! !Wearing our foul weather gear (just in case), we walked along the waterfront to the Robert Morris Inn (by the ferry dock) for dinner. It was really a nice evening although damp and a little overcast. One of the houses along the street had some BIG binoculars trained out on the Tred Avon - on a tripod - the large end lenses looked as big as saucers. ! !We dined by the window in the Tap Room. This is another expensive fancy place (we were put in the Tap Room because that was 'more casual' although the menu was the same). ! !Bob had a house salad ($5) and the fisherman's appetizer as a main course ($8.50 - fried clams, shrimp and scallops). I had a combination dish (can't remember the name - surf and something) which consisted of an *excellent* broiled lump crab meat crab cake (a la Robert Morris - apparently they do two types - and Oxford crab cake and a Robert Morris crab cake) and a grilled chicken breast. I didn't eat the chicken - saved it for lunch the next day. I couldn't figure out what was in the crab cake other than crab. It was a wonder to me that it even stuck together. My dinner cost $19. It was one of the lowest cost items on the menu. ! !With it, I also got a nice warm hard roll, a corn muffin, asparagus, fried zucchini, and something mashed which I think was rutabaga or some root vegetable that I don't normally like, but which was good. I ordered the chicken and crab because it was cheaper than just the crab by itself. Go figure. I had strawberry pie for dessert and Bob had coconut key lime cake. ! !As we walked back we had a friendly discussion/argument about how many boats were anchored where we had anchored last time, and whether they had anchor lights or not. One (which Bob didn't see at first) didn't have any light visible to us, and one apparently had an oil light that went out as we watched. in, not a good combination. Probably the best anchor for conditions like that is something with lots of fluke area, perhaps a large, oversized Fortress. Since they can be dissassembled, it is not that difficult to carry around a big one for "special" conditions. Something like their FX-85 would give you a great deal of holding power and only weighs 21 pounds. http://www.fortressanchors.com/fortr...hor_guide.html http://www.fortressanchors.com/safe_anchoring.html One of the anchorages in the Back Creek area of Solomons is right near the museum. It used to be that you could not go to the museum by dinghy - you had to approach by land and pay admission before you could land a dinghy. I think that has changed now. In any case, this is very protected, and also near to things like grocery stores for provisioning. The anchorage area has been reduced in recent years by the installation of moorings. http://p.vtourist.com/1547007-Anchor...ons_Island.jpg http://p.vtourist.com/3558627-Sports...ons_Island.jpg We anchored in Mill Creek off Back Creek. (one of many, many Back Creek's in the Bay area) where we waited out a storm. The area is nice and sheltered, but you still need to set your anchor well. There were 5 or 6 boats there with us, and we were the only ones that did not drag. Photo http://p.vtourist.com/3558630-My_pic...ons_Island.jpg shows Charlie checking his anchor - he had to pull it and reset it. We have a 55 lb. SuperMax anchor and all chain, and we did not move. http://p.vtourist.com/3558629-Calver...ons_Island.jpg |
October 26 - What A Drag!
On Fri, 26 Oct 2007 14:42:35 -0000, tom wrote:
Correction: FX-37 is 21 lbs, the FX-85 is 47lbs And you are correct, my eyes crossed the kg row with the pounds row. It turns out the FX-85 is 21.2 kg. |
October 26 - What A Drag!
"Rosalie B." wrote in message ... Wayne.B wrote: [snipped] The area is nice and sheltered, but you still need to set your anchor well. There were 5 or 6 boats there with us, and we were the only ones that did not drag. Photo http://p.vtourist.com/3558630-My_pic...ons_Island.jpg shows Charlie checking his anchor - he had to pull it and reset it. Hi Rosalie Is that a Cabo Rico? I'm curious as we don't see many over here in WA thanks Hoges in WA |
October 26 - What A Drag!
"Hoges in WA" wrote:
"Rosalie B." wrote in message .. . Wayne.B wrote: [snipped] The area is nice and sheltered, but you still need to set your anchor well. There were 5 or 6 boats there with us, and we were the only ones that did not drag. Photo http://p.vtourist.com/3558630-My_pic...ons_Island.jpg shows Charlie checking his anchor - he had to pull it and reset it. Hi Rosalie Is that a Cabo Rico? I'm curious as we don't see many over here in WA No, we have a CSY as do Charlie and Ernie that were referred to. One of them was for sale in Australia not so long ago. grandma Rosalie S/V RosalieAnn, Leonardtown, MD CSY 44 WO #156 http://home.mindspring.com/~gmbeasley/id1.html |
October 26 - What A Drag!
On Oct 26, 6:32 am, Skip Gundlach wrote:
October 26 - What A Drag! Skip Dear Skip.................................. Please supply the following data; 1) what is the weight of your boat? 2) How much DRAG (pull on your ground tackle) does your boat create in the following winds 15 knots _________ pounds 30 knots _________ pounds 42 knots _________ pounds 60 knots_________ pounds What is the SAFE WORKING LOAD of your chain AND conections (shackles) and any eye splices. "purdy strong" wont work. I need pounds rated for EACH item in your anchoring system.... or what normal people call "ground tackle." Can you tell me exactly what type bottom youre over??? HOw would you find out if you dont know? If you say look at a chart youre only 20% right. If you can not supply the requested information simply kiss your ass goodbuy. NOw for some other comments................................ The weight of your anchor is not the only consideration when calculating "holding ability" ANchoring is NOT rocket science NOR a magical art. Its just plain old fassioned RIGGING! and i dont mean rigging as the yachting group defines it. To be honest most choker setters know more about rigging than the average "captain" on every sail boat Ive talked to. ANd ya cant get more stupid than a choker setter.! Hell, guys have been dragging ships off beaches for hundreds of years. How do they do that???? A few anchors, some wire rope, a purchase or two. If a bunch of a two pack a day alcoholic thick knecked salvors can do it a Bank President with a univesity degree should be able to figure it out dont ya think Skip? To think all you need is an Acme FX 99 anchor to keep yo from draging is naive at best. Dear SKIP............... go read the following book and stop making such a public fool of yourself. "The Complete Book of Anchoring and Mooring", by Earl Hintz, Bob |
October 26 - What A Drag!
Bob,
What a bunch of crap! How many people do you think actually know any of the stuff that you're asking, other than the wight of their boat? According to my logs, I've anchored in over 400 separate locations throughout the Caribbean and the US, and without knowing the answers to your questions, I've only managed to drag a handful of times. I've been in storms at anchor that have reached 72 kts and have bent my anchor roller assembly like a pretzel. See http://www.geoffschultz.org/2002 _Sailing/Honduras_Roatan/imagepages/image24.htm What I do know is that I buy the highest quality components that I can and I make sure that the load ratings match. There will always be a weakest link, which will rear it's ugly head in those worst of circumstances, but that isn't what this discussion is about. I've cruised the Chesapeake and know that most towns only have 1-2 anchorages. In places like the Chesapeake I utilize cruising/anchoring guides that provide me with basic information such as the holding. Do I *know* what the bottom is? NO (but I'd bet it's mud in the Chesapeake), so I'll rely on data gathered from people who have anchored there before. Can I be sure that I didn't hook a plastic bag, tire, or who knows what? No! Can I practice good anchoring techniques such as using appropriate scope and backing down sufficiently hard? YES! I used to utilize a 45 lb CQR as my primary anchor, but I replaced it with a 25 KG Rocna and absolutely love the new anchor. I've been in anchorages where other boats with CQRs were dragging and we stayed put. If I was in turtle grass over sand, I always had to hand set the CQR, but I don't have to do that with the Rocna. I'm thoroughly impressed. Skip certainly has had more than his share of problems, and many of them are self inflicted, but he's out there doing it and hopefully learning from his mistakes. Many of the so-called experts in this forum spend all of their time behind a computer and quote text books instead of actually cruising. Maybe Skip is crazy by documenting his adventures and misfortunes in such a public fashion, but I give him credit for not giving up. -- Geoff Bob wrote in news:1193467621.642831.28750 @e9g2000prf.googlegroups.com: On Oct 26, 6:32 am, Skip Gundlach wrote: October 26 - What A Drag! Skip Dear Skip.................................. Please supply the following data; 1) what is the weight of your boat? 2) How much DRAG (pull on your ground tackle) does your boat create in the following winds 15 knots _________ pounds 30 knots _________ pounds 42 knots _________ pounds 60 knots_________ pounds What is the SAFE WORKING LOAD of your chain AND conections (shackles) and any eye splices. "purdy strong" wont work. I need pounds rated for EACH item in your anchoring system.... or what normal people call "ground tackle." Can you tell me exactly what type bottom youre over??? HOw would you find out if you dont know? If you say look at a chart youre only 20% right. If you can not supply the requested information simply kiss your ass goodbuy. NOw for some other comments................................ The weight of your anchor is not the only consideration when calculating "holding ability" ANchoring is NOT rocket science NOR a magical art. Its just plain old fassioned RIGGING! and i dont mean rigging as the yachting group defines it. To be honest most choker setters know more about rigging than the average "captain" on every sail boat Ive talked to. ANd ya cant get more stupid than a choker setter.! Hell, guys have been dragging ships off beaches for hundreds of years. How do they do that???? A few anchors, some wire rope, a purchase or two. If a bunch of a two pack a day alcoholic thick knecked salvors can do it a Bank President with a univesity degree should be able to figure it out dont ya think Skip? To think all you need is an Acme FX 99 anchor to keep yo from draging is naive at best. Dear SKIP............... go read the following book and stop making such a public fool of yourself. "The Complete Book of Anchoring and Mooring", by Earl Hintz, Bob -- -- Geoff www.GeoffSchultz.org |
October 26 - What A Drag!
On Oct 27, 2:47 am, Bob wrote:
On Oct 26, 6:32 am, Skip Gundlach wrote: October 26 - What A Drag! Skip Dear Skip.................................. Please supply the following data; 1) what is the weight of your boat? 2) How much DRAG (pull on your ground tackle) does your boat create in the following winds 15 knots _________ pounds 30 knots _________ pounds 42 knots _________ pounds 60 knots_________ pounds What is the SAFE WORKING LOAD of your chain AND conections (shackles) and any eye splices. "purdy strong" wont work. I need pounds rated for EACH item in your anchoring system.... or what normal people call "ground tackle." Can you tell me exactly what type bottom youre over??? HOw would you find out if you dont know? If you say look at a chart youre only 20% right. If you can not supply the requested information simply kiss your ass goodbuy. NOw for some other comments................................ The weight of your anchor is not the only consideration when calculating "holding ability" ANchoring is NOT rocket science NOR a magical art. Its just plain old fassioned RIGGING! and i dont mean rigging as the yachting group defines it. To be honest most choker setters know more about rigging than the average "captain" on every sail boat Ive talked to. ANd ya cant get more stupid than a choker setter.! Hell, guys have been dragging ships off beaches for hundreds of years. How do they do that???? A few anchors, some wire rope, a purchase or two. If a bunch of a two pack a day alcoholic thick knecked salvors can do it a Bank President with a univesity degree should be able to figure it out dont ya think Skip? To think all you need is an Acme FX 99 anchor to keep yo from draging is naive at best. Dear SKIP............... go read the following book and stop making such a public fool of yourself. "The Complete Book of Anchoring and Mooring", by Earl Hintz, Bob Hi, Bob, and group, Answers to your questions: 1) Boat as built was 33K, but with all the stuff, I presume to be at about 40K. No lift ever showed that much - but I can't believe it any less. Yes, I know, that's not a scientifically sound answer, but absent calibrated strain guages and a specific project to determine that, I doubt I'll ever know - at least not without putting it in a very carefully calibrated tank to measure the displacement. In any case, the windage, at least to me, would be the more significant issue. Not being an engineer (perhaps Roger, or you, if you are one, too) could tell me if that's a reasonable premise. 2) I have not put a strain guage, not owning one, on my chain. Further, thanks, I've not (yet) been in anything - at anchor - which exceeded 40 knots. Again, if I had the calculated windage, and the proper means (not an engineer) of calculation of wind forces I could probably tell you - but I can't. The SWL on the shackles and swivels is well in excess of my chain, which is all 5/16HT, G40 hotdipped galvanized, which SWL I don't recall at the moment. However, at the time I sized it/them, the chain was sufficient by all popular measures, and the swivels and shackles, what with my not wanting to have the weakest point at the anchor, were well over that. I gave several vendors a hard time when they couldn't be definitive about the SWL, until I got very specific information on the parts I bought. Generally speaking, other than chain, which if I did would be unwieldy for the weight, I've gone at least one size larger than recommended, which is how I wound up with 130# of anchor on the bow rollers. As to eye splices, we have only one on the bow, and that's on the secondary anchor, which has in front of it 175' of the aforementioned stuff. That is to a size up from recommended, not 5/8 but 3/4 MegaBraid, spliced properly. There's not a better way to do it and have it go through the gypsy, so it's as good as it's going to get without that side being all chain as well. New England Rope feels very confident in that method of splice, so, as I can't prove them wrong, it's what I did. Our snubbers are in one case 5/8 threestrand on a logging hook, and 3/4 MegaBraid as above on a rather more hightech hook designed for 5/16. When we back down, including on the earlier mentioned adventures, it stretches very significantly. No, I don't know the SWL on those, either, but I did at the time. I'm not going to bother to look it up for this exercise. As to the supplementary anchoring gear, we have a Fortress 37, a CQR45, and two smaller danforths, along with rode bags. Those have the aforementioned MegaBraid and 3/8BBB as which came with the boat as built, but only about 30', as to carry that in the dink would be problematic for more. I have additional hundreds of feet of both 3/4 Megabraid and 5/8 threestrand aboard to extend the 300' standard on all our rodes, whether all chain or part. As to finding out exactly what kind of bottom I'm over, throwing a small anchor overboard, setting it hard (and dragging, as would be possible with a small one other than hooked terminally on some rock or other obstruction), motoring over it and then pulling it up to inspect what came up would be my favored one in waters other than conducive to diving. As my current professor, however, I expect you'll correct me as to the actual proper means. Local knowledge might help, but I've learned to be very distrustful of LN, as, from what I've gotten and experienced, it's many times either wrong or malicious. As to your other comments, I believe I'm aware of what you mentioned, other than I don't know the term "Choker Setter" - a clear deficiency in my education which I will work diligently to remedy. As to reading, I agree that the Hinz (Hintz?) book will be worth acquiring - but I've not yet crossed its path. The Seven Seas flea market at Annapolis provided me with two others I've been seeking, Storm Tactics (on which much storm has been occasioned in these parts recently) and Heavy Weather Sailing. As to being a public fool, how else would I get publicly taken properly to task so I could become less of one in private??? :{)) L8R Skip PS are you a character in a Steven Patsis-created strip's character's occasional novelizations? Certainly, nearly anything I read suggests a match... Morgan 461 #2 SV Flying Pig KI4MPC See our galleries at www.justpickone.org/skip/gallery ! Follow us at http://groups.google.com/group/flyingpiglog and/or http://groups.yahoo.com/group/TheFlyingPigLog "You are never given a wish without also being given the power to make it come true. You may have to work for it however." (and) "There is no such thing as a problem without a gift for you in its hands. You seek problems because you need their gifts." (Richard Bach, in The Reluctant Messiah) |
October 26 - What A Drag!
On Oct 27, 2:47 am, Bob wrote:
On Oct 26, 6:32 am, Skip Gundlach wrote: October 26 - What A Drag! Skip Dear Skip.................................. Please supply the following data; 1) what is the weight of your boat? 2) How much DRAG (pull on your ground tackle) does your boat create in the following winds 15 knots _________ pounds 30 knots _________ pounds 42 knots _________ pounds 60 knots_________ pounds What is the SAFE WORKING LOAD of your chain AND conections (shackles) and any eye splices. "purdy strong" wont work. I need pounds rated for EACH item in your anchoring system.... or what normal people call "ground tackle." Can you tell me exactly what type bottom youre over??? HOw would you find out if you dont know? If you say look at a chart youre only 20% right. If you can not supply the requested information simply kiss your ass goodbuy. NOw for some other comments................................ The weight of your anchor is not the only consideration when calculating "holding ability" ANchoring is NOT rocket science NOR a magical art. Its just plain old fassioned RIGGING! and i dont mean rigging as the yachting group defines it. To be honest most choker setters know more about rigging than the average "captain" on every sail boat Ive talked to. ANd ya cant get more stupid than a choker setter.! Hell, guys have been dragging ships off beaches for hundreds of years. How do they do that???? A few anchors, some wire rope, a purchase or two. If a bunch of a two pack a day alcoholic thick knecked salvors can do it a Bank President with a univesity degree should be able to figure it out dont ya think Skip? To think all you need is an Acme FX 99 anchor to keep yo from draging is naive at best. Dear SKIP............... go read the following book and stop making such a public fool of yourself. "The Complete Book of Anchoring and Mooring", by Earl Hintz, Bob Hi, Bob, and group, Answers to your questions: 1) Boat as built was 33K, but with all the stuff, I presume to be at about 40K. No lift ever showed that much - but I can't believe it any less. Yes, I know, that's not a scientifically sound answer, but absent calibrated strain guages and a specific project to determine that, I doubt I'll ever know - at least not without putting it in a very carefully calibrated tank to measure the displacement. In any case, the windage, at least to me, would be the more significant issue. Not being an engineer (perhaps Roger, or you, if you are one, too) could tell me if that's a reasonable premise. 2) I have not put a strain guage, not owning one, on my chain. Further, thanks, I've not (yet) been in anything - at anchor - which exceeded 40 knots. Again, if I had the calculated windage, and the proper means (not an engineer) of calculation of wind forces I could probably tell you - but I can't. The SWL on the shackles and swivels is well in excess of my chain, which is all 5/16HT, G40 hotdipped galvanized, which SWL I don't recall at the moment. However, at the time I sized it/them, the chain was sufficient by all popular measures, and the swivels and shackles, what with my not wanting to have the weakest point at the anchor, were well over that. I gave several vendors a hard time when they couldn't be definitive about the SWL, until I got very specific information on the parts I bought. Generally speaking, other than chain, which if I did would be unwieldy for the weight, I've gone at least one size larger than recommended, which is how I wound up with 130# of anchor on the bow rollers. As to eye splices, we have only one on the bow, and that's on the secondary anchor, which has in front of it 175' of the aforementioned stuff. That is to a size up from recommended, not 5/8 but 3/4 MegaBraid, spliced properly. There's not a better way to do it and have it go through the gypsy, so it's as good as it's going to get without that side being all chain as well. New England Rope feels very confident in that method of splice, so, as I can't prove them wrong, it's what I did. Our snubbers are in one case 5/8 threestrand on a logging hook, and 3/4 MegaBraid as above on a rather more hightech hook designed for 5/16. When we back down, including on the earlier mentioned adventures, it stretches very significantly. No, I don't know the SWL on those, either, but I did at the time. I'm not going to bother to look it up for this exercise. As to the supplementary anchoring gear, we have a Fortress 37, a CQR45, and two smaller danforths, along with rode bags. Those have the aforementioned MegaBraid and 3/8BBB as which came with the boat as built, but only about 30', as to carry that in the dink would be problematic for more. I have additional hundreds of feet of both 3/4 Megabraid and 5/8 threestrand aboard to extend the 300' standard on all our rodes, whether all chain or part. As to finding out exactly what kind of bottom I'm over, throwing a small anchor overboard, setting it hard (and dragging, as would be possible with a small one other than hooked terminally on some rock or other obstruction), motoring over it and then pulling it up to inspect what came up would be my favored one in waters other than conducive to diving. As my current professor, however, I expect you'll correct me as to the actual proper means. Local knowledge might help, but I've learned to be very distrustful of LN, as, from what I've gotten and experienced, it's many times either wrong or malicious. As to your other comments, I believe I'm aware of what you mentioned, other than I don't know the term "Choker Setter" - a clear deficiency in my education which I will work diligently to remedy. As to reading, I agree that the Hinz (Hintz?) book will be worth acquiring - but I've not yet crossed its path. The Seven Seas flea market at Annapolis provided me with two others I've been seeking, Storm Tactics (on which much storm has been occasioned in these parts recently) and Heavy Weather Sailing. As to being a public fool, how else would I get publicly taken properly to task so I could become less of one in private??? :{)) L8R Skip PS are you a character in a Steven Patsis-created strip's character's occasional novelizations? Certainly, nearly anything I read suggests a match... Morgan 461 #2 SV Flying Pig KI4MPC See our galleries at www.justpickone.org/skip/gallery ! Follow us at http://groups.google.com/group/flyingpiglog and/or http://groups.yahoo.com/group/TheFlyingPigLog "You are never given a wish without also being given the power to make it come true. You may have to work for it however." (and) "There is no such thing as a problem without a gift for you in its hands. You seek problems because you need their gifts." (Richard Bach, in The Reluctant Messiah) |
October 26 - What A Drag!
On Sat, 27 Oct 2007 06:47:01 -0000, Bob wrote:
Please supply the following data; 1) what is the weight of your boat? 2) How much DRAG (pull on your ground tackle) does your boat create in the following winds 15 knots _________ pounds 30 knots _________ pounds 42 knots _________ pounds 60 knots_________ pounds ... Bob You must be joking? This is the sort of questionnaire that an engineer might address. I will tell you for free, that the rec.boats.cruising participation group is not largely comprised of engineers. You have this data for your boat, I expect. Accurate to +- 5% I expect? Brian Whatcott Altus OK p.s. Drag is determined by a whole bunch more factors than wind speed, dude. |
October 26 - What A Drag!
As to a GPS anchor watch I note these two incidents:
A couple of years ago my wife and I took a walk down an old power line that was over grown but had a trail. I took my pocket GPS with me and logged the track. The outgoing and return tracks were off by at least 150 yards in places. Not big jumps but just gradually wandering off. As I was walking a very narrow path through otherwise dense forest I know I was traveling the exact same path. A couple of days later I unintentionally left the GPS plugged into my car overnight with the track turned on. The next morning I had a "scatter plot" for my track covering a couple of hundred yards. The GPS (Magellan) has AIS and has been dead accurate in every other instance. I use it to find deer stands in the dark when hunting - going out in the morning before sunrise. The point is that GPS SYSTEM, though phenomenally accurate MOST of the time can fail SOME of the time. I have thought of this when using the anchor alarm. I might be dragging or the GPS SYSTEM might be brain farting. A final point, oft made by Nigel Calder, not all charts are normalized to the same datum. For example, through first hand experience, and as noted on the charts, the South coast of Newfoundland charts Lat/Lon can vary by as much as 1/2 mile from the GPS position. It is not a simple conversion factor, the CGS does not know what the origional datum was. It baffles me how the CGS allows this to continue but it does. If you are interested I took a picture of my plotter which I posted here. http://ph.groups.yahoo.com/group/sho...os/browse/bd9e Howard |
October 26 - What A Drag!
"Skip Gundlach" wrote in message oups.com... On Oct 27, 2:47 am, Bob wrote: On Oct 26, 6:32 am, Skip Gundlach wrote: If a bunch of a two pack a day alcoholic thick knecked salvors can do it a Bank President with a univesity degree should be able to figure it out dont ya think Skip? Hey Skip Were you a Bank President? What Bank? Just curious. I work for a Bank in Oz and for many years while working for another bank was a member of Robert Morris. Hoges in WA as in Western Australia. By the way, you keep finding all sorts of place where the holding's not so good. My wife and I will be going up the east coast of the US in a couple of years and anywheres you come to grief I'm going to pay particular attention to. |
October 26 - What A Drag!
The point is that GPS SYSTEM, though phenomenally accurate MOST of the
time can fail SOME of the time. More likely your unit wasn't picking up enough satellites. This is not the fault of the GPS system. Some older units didn't do a very good job of pickup up sats when there's overhead leaf canopy (some still don't). Don't blame the system for inferior equipment. An anchor watch in open water, without high terrain or foliage nearby, will likely be very consistent in it's location. If you are interested I took a picture of my plotter which I posted here. http://ph.groups.yahoo.com/group/sho...os/browse/bd9e Which is a useless link unless someone joins that group. Try using a free service like flickr instead of forcing people to join (and presumably then leave) a group. |
October 26 - What A Drag!
hpeer wrote:
As to a GPS anchor watch I note these two incidents: Someone asked Skip if he kept an anchor watch. Normally once we are anchored, the anchor watch is my responsibility. Probably because once Bob is asleep, he's asleep. This is roughly what I do. I leave the GPS in the cockpit on (plugged in to the pedestal), down to the greatest magnification that it has, and I mark where it shows that we are anchored, and label the mark. I also mark and label the anchor spot on the electronic charts on the computer. If we are anchored near any kind of civilization, I take mental bearings on the various shore points that I can see and note their relationship to the boat. When I go down into the cabin, I look out the ports next to me when I'm in bed and note what I see from there. Periodically I will wake up and look out the port I can look out the port without really getting up, but if what I see is different from what I expect to see, I will go up into the cockpit and look at the track on the GPS. (I can wake myself up on schedule without an alarm - the interval of waking decreases i.e. I wake more- often as the hazard that I perceive increases.) I wake more often in high wind or if we have something closer to us. I do have a kind of alarm, in that if the wind picks up at night, the wind gen will 'signal' by way of increased noise and vibration which we hear in the cabin (you can't hear it in the cockpit, but the radar arch where the wind gen is mounted transmits the vibration to the deck). The only times we've ever dragged after the anchor has been set has been when we were anchored for lunch. But if I were to be concerned about where we were, I'd wake Bob up. Bob is very picky about where he sets the anchor (depth of water and type of bottom), and I back down on it until he is satisfied that it is well set. We usually get up early and stop well before dark, especially on the way south because not only does it get dark earlier in the fall, but the sun gets in your eyes otherwise because it is so low in the sky at this time of year.. We have anchored at dusk, but we have only (AFAI remember) anchored after dark-dark once, and that was when we were coming up from Indian Key to Miami and we were going to have a storm for the next few days. We wanted to be out of the Hawk Channel before the bulk of the storm hit. We were sailing a little faster than usual because of the wind. March 22, 2004 We got up about 0630. Bob is becoming more worried about the mooring and says he would rather be at anchor. I am very anxious to tour Indian Key (which we missed doing on the way down because we were in such a hurry to get to Marathon), but I actually agree with him, although I don't say so. The problem is that we know from experience there is NO protection from NE or E winds in Hawk Channel (that we can get to) except possibly Rodriguez Key which is really close by. I don't think we will be any better off anchored there than we would be on a mooring as it is quite rocky with poor holding. And it usually takes us two days to get from here to Miami.. I finally give in and tell Bob that we can go. We got underway about 0745 which is a bit later than usual if we expect a long day. We get to Tavernier at 1000. It is way too early to stop. Where can we go for the night? I'm considering the options. We can see Rodriguez ahead. I suggest that if we are willing to anchor after dark, we might be able to get all the way to Miami tonight. Bob is really happy with that idea. cut what I wrote about the trip The wind really picked up from the oncoming storm about 1700. About 1930, we have come up Biscayne Bay to Miami, and it is dark. I have picked out a place to anchor in an indentation off Hurricane Harbor which is at the west side of Key Biscayne. Bob has prepared the anchor, taken in the sails, and handed the helm over to me to find a spot to anchor. I motor in watching the ATON on the radar and our position on the electronic chart. Bob is standing in the forward companionway trying to pick out the flashing lights on the marks. Finally about in the middle of the area (I really want to be closer to shore, but I'm chicken to go any farther in), I'm ready to have Bob drop the hook. It sets quickly and firmly. We have done 73.6 sm (64nm) at an average speed of 6.2 mph. It is now really windy |
October 26 - What A Drag!
Hoges in WA wrote:
"Skip Gundlach" wrote in message .... By the way, you keep finding all sorts of place where the holding's not so good. My wife and I will be going up the east coast of the US in a couple of years and anywheres you come to grief I'm going to pay particular attention to. The holding is just fine. Skip's problem is that he's using a Delta in soft mud where it is not at its best. I use a Delta all the time in New England where the bottom is somewhat thicker, but in the soft Chesapeake mud a Danforth style is needed. A Fortress is good, especially when the flukes are set at the "mud" angle. However, they can have a problem resetting if the mud is too thick, or if the flukes have been fouled. A good approach, then, is to set two anchors off the bow - one Delta or CQR that will reset and at worst only drag slowly, and one Fortress that will dig deep in the soft mud. Either of the anchors should hold if well set; both of them guarantees an anxiety-free night. I carry a 35# Delta on 50 feet of chain plus a Fortress FX23 with only a short chain ready on deck. You really don't want big chain on the mud anchor because that can prevent it from digging in quickly. Also, the Fortress shouldn't be too big because it will be deployed by hand, possibly even rowed out. Usually I just power over to Port and drop the the Fortress, but I've rowed or even walked it to a good spot. Having a big heavy second anchor is not good incentive to actually using it - Skip's experience is a case in point. |
October 26 - What A Drag!
On Oct 27, 6:16 am, Brian Whatcott wrote:
On Sat, 27 Oct 2007 06:47:01 -0000, Bob wrote: Please supply the following data; 1) what is the weight of your boat? 2) How much DRAG (pull on your ground tackle) does your boat create in the following winds 15 knots _________ pounds 30 knots _________ pounds 42 knots _________ pounds 60 knots_________ pounds .. Bob You must be joking? This is the sort of questionnaire that an engineer might address. I will tell you for free, that the rec.boats.cruising participation group is not largely comprised of engineers. You have this data for your boat, I expect. Accurate to +- 5% I expect? Brian Whatcott Altus OK p.s. Drag is determined by a whole bunch more factors than wind speed, dude.- Hide quoted text - Hi Brian: No Joke intended here. And in all sincerity I don't believe my questions are beyond anyone that lingers here. Like I said, It aint rocket science. The biggest problem I see here is a total lack of ability/desire to learn................ There are those who say theyve anchored 400 times/year all over the place and bla bla bla or its beyond our ability to learn cause we aint engineers. or Uhh, duhh I dont know... weve drug a few times without any problmes So once a gain I will say that operating a boat does has a prereq skill set. You have this data for your boat, I expect. Accurate to +- 5% I expect? To answer your question Brian...... Yes I do have that info. Im not an engineer, just a average joe who doesnt have enough money to risk my home getting carried to the rocks. Ill tell ya a little secret....... I read it in a book. A book an engineer wrote so I didnt have to do the math. THere are some very smart people out there all willing to help. So I read and take their advice. The BIGGEST problem with that is any idiot can get $500 bucks for an article in Sailing or Cruising World. The real challenge is which source to believe. So as I said to Skip I will also say to you. Please read the text titled: "The Complete Book of Anchoring and Mooring", by Earl Hintz, He has another titled " Sea Anchors and Drogues" Get that one too. Once you read both then lets talk.................. PS, Agreed there are several factors, when put together, keep a boat put..... dude. But figured that was beyond Skips ability to understand at this point. |
October 26 - What A Drag!
On Oct 27, 5:57 am, Skip Gundlach wrote:
On Oct 27, 2:47 am, Bob wrote: Hi, Bob, and group, Answers to your questions: 1) Boat as built was 33K, but with all the stuff, I presume to be at about 40K. That works. Thank you. 2) I have not put a strain guage, not owning one, on my chain. That is not necessary. IF you have read : "The Complete Book of Anchoring and Mooring", by Earl Hintz, The SWL on the shackles and swivels is well in excess of my chain, This I do not belive......................... How can you get a shackel pin that equals the BREAKING STRENGTH of chain tthrough the 5/16 chain link??? Try it. It dont work. That is unless........................ As to eye splices, we have only one on the bow, MegaBraid, spliced properly. According to who............. the Sampson Cordage Compny or the guy at West marine??? There's not a better way to do it and have it go through the gypsy, And there is your problem right there Skip. Ease and comfort compared to reliability and safety. You talk-talk-talk and make excuess but never seem to seek accurate info. Maybe having it go through the gypsy is not the ONLY/best way to do it. so it's as good as it's going to get without that side being all chain as well. New England Rope feels very confident in that method of splice, so, as I can't prove them wrong, it's what I did. They sell the stuff to guys like you knowing you DEMAND the line to go through a gypsy. Ever ask the England or Sampson people what the strengh of that attachment creates???? My guess is 60% at best. But ask the engeers at the company. As to the supplementary anchoring gear, we have a Fortress 37, a CQR45, and two smaller danforths, along with rode bags. Those have the aforementioned MegaBraid and 3/8BBB as which came with the boat as built, but only about 30', as to carry that in the dink would be problematic for more. I have additional hundreds of feet of both 3/4 Megabraid and 5/8 threestrand aboard to extend the 300' standard on all our rodes, whether all chain or part. But yet you almost ended up on the rocks again........... WHY??? As to finding out exactly what kind of bottom I'm over, throwing a small anchor overboard, setting it hard (and dragging, as would be possible with a small one other than hooked terminally on some rock or other obstruction), motoring over it and then pulling it up to inspect what came up would be my favored one in waters other than conducive to diving. As my current professor, however, I expect you'll correct me as to the actual proper means. No, I'll let that task to a more knowledgable person.... "The Complete Book of Anchoring and Mooring", by Earl Hintz, I don't know the term "Choker Setter" - a clear deficiency in my education which I will work diligently to remedy. No need. As to reading, I agree that the Hinz (Hintz?) book will be worth acquiring - but I've not yet crossed its path. For god sakes man. Just go to a book store and order it ! ! ! or go on line and order it Bob |
October 26 - What A Drag!
On Sat, 27 Oct 2007 12:59:39 -0400, Rosalie B.
wrote: hpeer wrote: As to a GPS anchor watch I note these two incidents: Someone asked Skip if he kept an anchor watch. Normally once we are anchored, the anchor watch is my responsibility. Probably because once Bob is asleep, he's asleep. This is roughly what I do. First, I have no experience in this, just reading. If I were close to other boats in a tight anchorage, I probably couldn't sleep except in ideal conditions without a watch. No matter how anchor savvy I thought I was. It seems that if Skip had a GPS alarm to would have avoided the 1/4 mile or so drift he just had. There's been a bit here recently written on GPS alarms, and some swear by it. But here's what I was thinking I might try, and maybe some here have thought of it or care to comment on it. No GPS dependency. A fishing sinker, maybe take 6-8 ounces to sit on the bottom withstanding tides. Nice if it can be deployed when the anchor is set down, near the anchor. But the anchor and rode can't foul it. At the other end is a fishing rod, with reel drag set loose. Once the line is out where swing won't unspool it further, a line from an alarm - could be a windup - is attached to the rod line. Might work. As I said, not for tight anchorages. Biggest issue would be to set it up so the rode and anchor can't foul the weight or fishing line keeping the alarm from sounding. False alarms because of debris snagging the fishing line might happen, but hey. Another thought is a sharp stick/rod stuck in the mud just upwind of the set anchor, and attach the fishing line end to that. Shallow water, proper suitable muck only. Won't work if the wind does a 180 and the anchor/rode fouls the stick. Same problem not getting the weight/fish line fouled. GPS might be the best, and what I'm talking about used as backup. Or discarded out of hand. --Vic |
October 26 - What A Drag!
Vic Smith wrote:
On Sat, 27 Oct 2007 12:59:39 -0400, Rosalie B. wrote: hpeer wrote: As to a GPS anchor watch I note these two incidents: Someone asked Skip if he kept an anchor watch. Normally once we are anchored, the anchor watch is my responsibility. Probably because once Bob is asleep, he's asleep. This is roughly what I do. First, I have no experience in this, just reading. If I were close to other boats in a tight anchorage, I probably couldn't sleep except in ideal conditions without a watch. No matter how anchor savvy I thought I was. In my younger days I slept so soundly I was terrified of sleeping through a grounding. On more than one occasion I forced myself to stay up for a late weather front or tide change. Now the "call of nature" gets me up several times. A telltale compass mounted above my bunk is handy if you suspect a shift. It seems that if Skip had a GPS alarm to would have avoided the 1/4 mile or so drift he just had. There's been a bit here recently written on GPS alarms, and some swear by it. But here's what I was thinking I might try, and maybe some here have thought of it or care to comment on it. No GPS dependency. A fishing sinker, maybe take 6-8 ounces to sit on the bottom withstanding tides. I used to have a small anchor attached to an old pot that would rattle around on deck. But there were too many false positives - I decided it was better to learn how to anchor securely. Actually, my new GPS is accurate enough that I might start using its alarm. |
October 26 - What A Drag!
On Sat, 27 Oct 2007 11:16:29 -0700, Bob wrote:
2) How much DRAG (pull on your ground tackle) does your boat create in the following winds .... You must be joking? This is the sort of questionnaire that an engineer might address. .... Hi Brian: No Joke intended here. And in all sincerity I don't believe my questions are beyond anyone that lingers here. Wow! An anwer in a tone so civil that its credibility jumps 5 points immediately. Thanks Brian W |
October 26 - What A Drag!
On Oct 27, 2:39 pm, Bob wrote:
2) I have not put a strain guage, not owning one, on my chain. That is not necessary. IF you have read : "The Complete Book of Anchoring and Mooring", by Earl Hintz, I wasn't able to find any author by that name. However, I have, now, read a 21-year-old text by that name and which had Earl Hinz, as I offered in my reply before, as the author. For someone as picky as you seem to be about exactitude, I assumed you meant what you wrote, not a careless error, repeated not once but twice later. A simple glance at what I presume to be the book from which you cribbed all the questions would have given you the proper spelling of his name. Don't insult the author with a misspelling. How'd you like to have your name be repeatedly misspelled as Boob, even after correcting the misspeller??. The SWL on the shackles and swivels is well in excess of my chain, This I do not belive......................... How can you get a shackel pin that equals the BREAKING STRENGTH of chain tthrough the 5/16 chain link??? Try it. It dont work. That is unless........................ Can't tell you that. I didn't do the design engineering and testing on the products I bought. However, when a product has both a label with the maker and whatever testing institute specifying a SWL greater than my chain, I don't engage an engineering firm to prove them wrong. Some things you have to take on faith. How do *YOU* attach your chain? As to eye splices, we have only one on the bow, MegaBraid, spliced properly. According to who............. the Sampson Cordage Compny or the guy at West marine??? According to New England Rope, the maker. Samson (there you go again - it's not samPson) Rope (not Cordage Company) (www.samsonrope.com - Samson Rope Technologies, Inc.) makes interesting stuff, but I don't have any of it aboard. If you'd like, I'll conduct a seminar on those splices. I'm reasonably good at it. It ain't rocket science. Chain, eye, deadeye/end or whatever you want to call it, it will look good and hold magnificently. Their pdf DCR 448 Initial Release, publication MISP87 will give you more information. For further reading you may enjoy S9086-UU-STM-010/CH-613R3, revision 3 or higher, NAVAL SHIPS' TECHNICAL MANUAL, CHAPTER 613, WIRE AND FIBER ROPE AND RIGGING, which addresses types of line (including wire) and splicing strengths for various types of splices. There's not a better way to do it and have it go through the gypsy, And there is your problem right there Skip. Ease and comfort compared to reliability and safety. You talk-talk-talk and make excuess but never seem to seek accurate info. Maybe having it go through the gypsy is not the ONLY/best way to do it. I didn't say it was the only way. I said it was the only way to have it go through the gypsy. I invite you to document (Hinz' over-20-year-old stuff doesn't address the state of the art today) a more effective way to make rope and chain continuous - not with a honking big thimble or other stuff in the middle of it. When I have all chain on the one which goes through the gypsy, all the time, and only have said splice in a location which would only see use in either extreme situations or very deep locations on the secondary or tertiary or quartenary applications said later two not using the windlass in any event, I don't get fussed about it. Further, as you've pointed out, chain doesn't have a very large aperture; putting a 3/4" line through a thimble or other chafe resistant device is even more difficult than finding some metal which will exceed the strength of the chain when you put its pin through it. so it's as good as it's going to get without that side being all chain as well. New England Rope feels very confident in that method of splice, so, as I can't prove them wrong, it's what I did. They sell the stuff to guys like you knowing you DEMAND the line to go through a gypsy. Ever ask the England or Sampson people what the strengh of that attachment creates???? My guess is 60% at best. But ask the engeers at the company. See the above references... As to the supplementary anchoring gear, we have a Fortress 37, a CQR45, and two smaller danforths, along with rode bags. Those have the aforementioned MegaBraid and 3/8BBB as which came with the boat as built, but only about 30', as to carry that in the dink would be problematic for more. I have additional hundreds of feet of both 3/4 Megabraid and 5/8 threestrand aboard to extend the 300' standard on all our rodes, whether all chain or part. But yet you almost ended up on the rocks again........... WHY??? Well, apparently several reasons. None are particularly important; I presume it to be that I misread a fouled anchor, when, instead, it was a lousy mud bottom which had done me in on the first pull. Not having sampled the bottom directly, but only by apparent set, I didn't know the nature of it as being - apparently, in hindsight - the same lousy stuff we abandoned on the other side of the channel when we first started on our time in Oxford, when we didn't set well, and I did, indeed, do the bottom sample, albeit with a 55# Delta. And there were no rocks in evidence nor anywhere in the vicinity as far as I could determine. Mud is reasonably forgiving, if not very good holding. It allows for a certain comfort level... The second anchoring was quite sufficient, in any case, even for the more severe wind conditions (yes, I know, severe is relative, and the conditions of what I had were not severe by hurricane, tropical cyclone or even storm [as varied from gale or half gale] circumstance) which presented following our reanchoring. As to finding out exactly what kind of bottom I'm over, throwing a small anchor overboard, setting it hard (and dragging, as would be possible with a small one other than hooked terminally on some rock or other obstruction), motoring over it and then pulling it up to inspect what came up would be my favored one in waters other than conducive to diving. As my current professor, however, I expect you'll correct me as to the actual proper means. No, I'll let that task to a more knowledgable person.... "The Complete Book of Anchoring and Mooring", by Earl Hintz, I can't find anything by him. However, in the book of the same name by Hinz, the author suggests sampling only a very small portion of only the surface. If you thought that duck consisted of a few inch circle of feathers, you'd be missing a pretty good meal, but that's what you'd get with his soap, grease or other sticky to pull up something from the bottom. I'll take a core sample or at least a foot or so of some other means, thanks. No, you're correct that I didn't do that in my second anchoring location; had I, I might have anchored differently. My bad. But then, again, I've never been shy about admitting those, have I? I don't know the term "Choker Setter" - a clear deficiency in my education which I will work diligently to remedy. No need. As to reading, I agree that the Hinz (Hintz?) book will be worth acquiring - but I've not yet crossed its path. For god sakes man. Just go to a book store and order it ! ! ! or go on line and order it Already read it. Well, already read what I presume you intended me to read, not something by a nonexistent Hintz. Interesting reading and I see that it's where you got all your questions. Now that I know how to find the means to calculate, perhaps I'll do that. Other than the minutiae of calculation, I didn't see anything in the book which was new information to me; I did see lots of old data/equipment and not the first word about third generation anchors which are available today... Now, if you'll excuse me, I'm going back to my movie. Bob L8R Skip Morgan 461 #2 SV Flying Pig KI4MPC See our galleries at www.justpickone.org/skip/gallery ! Follow us at http://groups.google.com/group/flyingpiglog and/or http://groups.yahoo.com/group/TheFlyingPigLog "You are never given a wish without also being given the power to make it come true. You may have to work for it however." (and) "There is no such thing as a problem without a gift for you in its hands. You seek problems because you need their gifts." (Richard Bach, in The Reluctant Messiah) |
October 26 - What A Drag!
Bill Kearney wrote:
The point is that GPS SYSTEM, though phenomenally accurate MOST of the time can fail SOME of the time. More likely your unit wasn't picking up enough satellites. This is not the fault of the GPS system. Some older units didn't do a very good job of pickup up sats when there's overhead leaf canopy (some still don't). Don't blame the system for inferior equipment. An anchor watch in open water, without high terrain or foliage nearby, will likely be very consistent in it's location. If you are interested I took a picture of my plotter which I posted here. http://ph.groups.yahoo.com/group/sho...os/browse/bd9e Which is a useless link unless someone joins that group. Try using a free service like flickr instead of forcing people to join (and presumably then leave) a group. You may well be correct that I was not picking up enough satellites. Although in this particular case there was not much overhead canopy, just a bunch of stunted (but dense) fir trees on either side. As I recall the number of satellites varies, some times more, some times fewer. And if the antenna does not have a clear view of the sky it may be off. I believe it is also possible for a reflection to cause an error, though probably not much of a problem unless you are in Miami. Still I take your point, lack of signal was the likely cause. Also, I said AIS when I meant to say WAAS - oops. No intent to make you join a useless group. Try http://s23.photobucket.com/albums/b384/hpeer/ if interested. I think that should work. Howard |
October 26 - What A Drag!
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October 26 - What A Drag!
Skip Gundlach wrote:
.... Well, apparently several reasons. None are particularly important; I presume it to be that I misread a fouled anchor, when, instead, it was a lousy mud bottom which had done me in on the first pull. Not having sampled the bottom directly, but only by apparent set, I didn't know the nature of it as being - apparently, in hindsight - the same lousy stuff we abandoned on the other side of the channel when we first started on our time in Oxford, when we didn't set well, and I did, indeed, do the bottom sample, albeit with a 55# Delta. Duh! What a coincidence - soft mud in two different parts of the Chesapeake! What are the odds of that? ''' I can't find anything by him. However, in the book of the same name by Hinz, the author suggests sampling only a very small portion of only the surface. If you thought that duck consisted of a few inch circle of feathers, you'd be missing a pretty good meal, but that's what you'd get with his soap, grease or other sticky to pull up something from the bottom. I'll take a core sample or at least a foot or so of some other means, thanks. Ah! Hinz is an incompetent bozo because he doesn't advise taking many core samples to figure out there's mud in the Chesapeake. No, you're correct that I didn't do that in my second anchoring location; had I, I might have anchored differently. My bad. But then, again, I've never been shy about admitting those, have I? For god sakes man. Just go to a book store and order it ! ! ! or go on line and order it Already read it. Well, already read what I presume you intended me to read, not something by a nonexistent Hintz. Interesting reading and I see that it's where you got all your questions. Now that I know how to find the means to calculate, perhaps I'll do that. Other than the minutiae of calculation, I didn't see anything in the book which was new information to me; Yes, it's clear you have the anchoring thing down pat now. I did see lots of old data/equipment and not the first word about third generation anchors which are available today... Skip, this has to rank amongst the dumbest things you've said here. Perhaps you can enlighten us as to how these "third generation anchors" have made Hinz's work obsolete. Now, if you'll excuse me, I'm going back to my movie. The time would be better spent reading a good book on anchoring. I suggest Hinz. |
October 26 - What A Drag!
On Sat, 27 Oct 2007 09:53:59 -0400, hpeer wrote:
A couple of days later I unintentionally left the GPS plugged into my car overnight with the track turned on. The next morning I had a "scatter plot" for my track covering a couple of hundred yards. You need a better GPS. Seriously. |
October 26 - What A Drag!
On Oct 27, 2:41 pm, Skip Gundlach wrote:
... I wasn't able to find any author by that name. However, I have, now, read a 21-year-old text by that name and which had Earl Hinz, as I offered in my reply before, as the author. ... Earl R Hinz is one of my heroes. He is an extraordinarily talented writer and researcher and has produced the seminal books on cruising in Oceania based on his own trailblazing travels. You may disagree with him, and there are a few thoughts of his that I take issue with, but he deserves more than an ordinary amount of respect. The last edition of _The Complete Book of Anchoring and Mooring_ came out in 2001. I have an older edition and I don't know if the new one mentions the newer anchors but even if it doesn't the fundamentals haven't been changed by them. I've been using a Spade for a few years now and it is a good anchor, but it is used in the same way as the Delta from which it was evolved. Not that anyone can learn to anchor by reading books alone, but the Hinz book on anchoring is worth a read and his articles and books on Pacific cruising are very good, indeed. Of course, I think Bob is being silly, but I hope that won't put you off Hinz. On a more or less unrelated topic, I use my GPS for anchor watch all the time. I've got a Furuno GP-31 and it has a simple graphic page that displays a "bread crumb" trail. I find that I can see where I dropped the anchor on that screen and put a goto point there. The anchor watch alarm is then set to go off if I go outside a circle around that point. While we sit at anchor the gps continues drawing the track on the screen and pretty soon a thick arc is drawn. This makes it very easy to see if we are dragging even if it is pitch black and raining as it so often is when a front passes by in the night... -- Tom. |
October 26 - What A Drag!
Hi, Jeff, and Group,
I probably shouldn't continue with this, as my name is already mud, ya know, but, just a couple of observations... On Oct 27, 10:36 pm, jeff wrote: Skip Gundlach wrote: ... Well, apparently several reasons. None are particularly important; I presume it to be that I misread a fouled anchor, when, instead, it was a lousy mud bottom which had done me in on the first pull. Not having sampled the bottom directly, but only by apparent set, I didn't know the nature of it as being - apparently, in hindsight - the same lousy stuff we abandoned on the other side of the channel when we first started on our time in Oxford, when we didn't set well, and I did, indeed, do the bottom sample, albeit with a 55# Delta. Duh! What a coincidence - soft mud in two different parts of the Chesapeake! What are the odds of that? This is the first time I've ever been in, let alone cruised the Chesapeake, and the only reason I was in it was to make the trip south a bit more interesting for my 82 year old Mother-in-Law, who joined us in NY on September 1. The ICW isn't my cup of tea. Having said that, we've enjoyed where we've been so far, and, as those who have been around long enough to have observed my style, anything which has happened which didn't kill me is merely part of life's fabric, and an adventure. So, I don't get very fussed about it, and instead, provide target practice for those who are better than I, and, sometimes, cautionary tales for those who haven't made my mistakes yet. My bad. Repetitively admitted. I'm unlikely to make the same mistake twice, whatever it is. ''' I can't find anything by him. However, in the book of the same name by Hinz, the author suggests sampling only a very small portion of only the surface. If you thought that duck consisted of a few inch circle of feathers, you'd be missing a pretty good meal, but that's what you'd get with his soap, grease or other sticky to pull up something from the bottom. I'll take a core sample or at least a foot or so of some other means, thanks. Ah! Hinz is an incompetent bozo because he doesn't advise taking many core samples to figure out there's mud in the Chesapeake. No. I was disputing the absolute certainty that the only way to find out what the bottom was composed of was to do a Hinz-stick maneuver. I don't agree with that as being sufficient information. I agree that it's a quick and dirty (muddy?) way to get some debris from the top of whatever you're over. I'm much more interested in what's underneath. No, you're correct that I didn't do that in my second anchoring location; had I, I might have anchored differently. My bad. But then, again, I've never been shy about admitting those, have I? For god sakes man. Just go to a book store and order it ! ! ! or go on line and order it Already read it. Well, already read what I presume you intended me to read, not something by a nonexistent Hintz. Interesting reading and I see that it's where you got all your questions. Now that I know how to find the means to calculate, perhaps I'll do that. Other than the minutiae of calculation, I didn't see anything in the book which was new information to me; Yes, it's clear you have the anchoring thing down pat now. Nor did I say that. I said I didn't see new (to me) information. As someone else in this thread has observed, reading and application are different things. Whether I knew something and applied all the knowledge are not necessarily congruent. I did see lots of old data/equipment and not the first word about third generation anchors which are available today... Skip, this has to rank amongst the dumbest things you've said here. Perhaps you can enlighten us as to how these "third generation anchors" have made Hinz's work obsolete. Nor did I say it was obsolete. However, to your point, and mine, which related to rode, the state of the art has changed since the edition I read. I was being taken to task for an inadequate (inferred) rode; it's my opinion that the cordage and hooks today are superior to that shown in the book I read as directed (assuming Bob merely has a twitchy "t" finger and isn't trying to have me read something else), and that what I have done to construct the several rodes we have aboard is sufficient to the task at hand. Now, if you'll excuse me, I'm going back to my movie. The time would be better spent reading a good book on anchoring. I suggest Hinz. Not a bad suggestion. And if you've bothered to read for content rather than merely to find something to shoot at, you'd have seen that I have done just that. However, having completed my assignment for the day, I went back to entertaining my two lady companions. For now, I'm considering whether I want to go out in nasty stuff (not dangerous), flying down to Solomons, or take another day in Cambridge and go to church, instead. L8R Skip Morgan 461 #2 SV Flying Pig KI4MPC See our galleries at www.justpickone.org/skip/gallery ! Follow us at http://groups.google.com/group/flyingpiglog and/or http://groups.yahoo.com/group/TheFlyingPigLog "You are never given a wish without also being given the power to make it come true. You may have to work for it however." (and) "There is no such thing as a problem without a gift for you in its hands. You seek problems because you need their gifts." (Richard Bach, in The Reluctant Messiah) |
October 26 - What A Drag!
On Sun, 28 Oct 2007 10:38:41 -0000, Skip Gundlach
wrote: For now, I'm considering whether I want to go out in nasty stuff (not dangerous), flying down to Solomons, or take another day in Cambridge and go to church, instead. Go for the prayers! :-) |
October 26 - What A Drag!
"Brian Whatcott" wrote
a tone so civil Did you catch the PS at the end? I sometimes wonder if the people who post evangelical "you must do as I say or you're a vile menace" rants are such confrontational jerks in person. I hope not. Bob may be a treasure trove of anchor wisdom for all I know, but when he comes off as just another troll with a hard-on for Skip, the credibility meter takes a dip. |
October 26 - What A Drag!
On Sun, 28 Oct 2007 10:38:41 -0000, Skip Gundlach
wrote: Hi, Jeff, and Group, I probably shouldn't continue with this, as my name is already mud Nope. Many here appreciate your journals, even the snipers. Just the nature of usenet. My compliments to you for your level-headedness in handling them, among your other travails. --Vic |
October 26 - What A Drag!
Vic Smith wrote:
On Sun, 28 Oct 2007 10:38:41 -0000, Skip Gundlach wrote: Hi, Jeff, and Group, I probably shouldn't continue with this, as my name is already mud Nope. Many here appreciate your journals, even the snipers. Just the nature of usenet. My compliments to you for your level-headedness in handling them, among your other travails. --Vic And for sharing your adventures with us. Richard |
October 26 - What A Drag!
On Oct 28, 8:15 am, "Ernest Scribbler"
wrote: "Brian Whatcott" wrote a tone so civil Did you catch the PS at the end? I sometimes wonder if the people who post evangelical "you must do as I say or you're a vile menace" rants are such confrontational jerks in person. I hope not. Bob may be a treasure trove of anchor wisdom for all I know, but when he comes off as just another troll with a hard-on for Skip, the credibility meter takes a dip. Ernie & Brian: Ah,, come on guys. I dont get to be an ass hole any place else. To be honest I have had a gut full of collegial congeniality. To be honest Skip reminds me too much of who Ive had to work with for the past 16 years. Well meaning, likable guys who go to church, smile and nod their heads then completely ignore some petty good advice from some pretty smart guys that post here (me excluded). I find it refreshing to say it the way it is. I wish for once he would just tell me to go get ****ed. I enjoyed someone's description of this place a few weeks ago. I can t remember the analogy but something close to, is like a bar that doesn't close and will let anybody make a fool of themselves without getting kicked out. I thought that was a right-on description. As far as my experience goes it may be a bit different than most yachters. I spent some time working with my Swedish step dad who commercial fished his 62' dragger off WA/OR; GOM diver mostly on scrap jobs (salvage) 10'-320'; American, Polish, Russian, Korean, Japanese factory trawlers in Bearing Sea. So I got to see lots of different ways to tie stuff together. I am by no means knowledgeable about anchoring. I've just seen lots of different ways to get a job done. Combine these experiences with my total lack of civil demeanor in this place makes for some pretty outlandish statements. Skip asked, what kind of shakels do I use attaching road to chain, chain to anchor. Two words: 1) Trawlex Grade 100 chain to anchor. Theyre cheep, small, and strong ie G100 compared to G40, an not galvanized. So I just swap it out once a year when I inspect my ground tackle. If a 400' factory trawler uses them to drag a 100 MT bag of Pollock out of the Bering Sea I think its good enough for my needs. 2) Nylite thimble (Samson) road to chain connection. If you don't know about these pretty PLEASE go to this link and take a look. The USCG use them on OR/WA/AK life boats. http://www.samsonrope.com/site_files/cm2004.pdf and no.... it wont go through your gypsy. But then I get a bullet proof 95-100% connection. And no I don't use three strand nylon for road. I use nylon double braid. Although I might go to some of the 12 plait products soon. Very easy/fast to splice and still get 10 percent stretch at 30% load. Oh, and tough as nails. Oh, and CHEAPER! There are lots of ways to do stuff. Just got to stay out of West Marine and Cruising World. So to all a sincere apology. Just don't look for a change any time soon in my phatic conversation style. Bombastic Bob |
October 26 - What A Drag!
On Sun, 28 Oct 2007 10:15:17 -0600, Vic Smith
wrote: On Sun, 28 Oct 2007 10:38:41 -0000, Skip Gundlach wrote: Hi, Jeff, and Group, I probably shouldn't continue with this, as my name is already mud Nope. Many here appreciate your journals, even the snipers. Just the nature of usenet. My compliments to you for your level-headedness in handling them, among your other travails. --Vic What he said. Brian W |
October 26 - What A Drag!
On Sun, 28 Oct 2007 12:15:04 -0400, "Ernest Scribbler"
wrote: "Brian Whatcott" wrote a tone so civil Did you catch the PS at the end? I sometimes wonder if the people who post evangelical "you must do as I say or you're a vile menace" rants are such confrontational jerks in person. I hope not. Bob may be a treasure trove of anchor wisdom for all I know, but when he comes off as just another troll with a hard-on for Skip, the credibility meter takes a dip. It was a benefit of the doubt thing. I know where you're comnig from. Brian W |
GPS Errors and Anchor watch; was: October 26 - What A Drag!
In article om,
says... On Oct 27, 2:41 pm, Skip Gundlach wrote: ... I wasn't able to find any author by that name. However, I have, now, read a 21-year-old text by that name and which had Earl Hinz, as I offered in my reply before, as the author. ... Earl R Hinz is one of my heroes. He is an extraordinarily talented writer and researcher and has produced the seminal books on cruising in Oceania based on his own trailblazing travels. You may disagree with him, and there are a few thoughts of his that I take issue with, but he deserves more than an ordinary amount of respect. The last edition of _The Complete Book of Anchoring and Mooring_ came out in 2001. I have an older edition and I don't know if the new one mentions the newer anchors but even if it doesn't the fundamentals haven't been changed by them. I've been using a Spade for a few years now and it is a good anchor, but it is used in the same way as the Delta from which it was evolved. Not that anyone can learn to anchor by reading books alone, but the Hinz book on anchoring is worth a read and his articles and books on Pacific cruising are very good, indeed. Of course, I think Bob is being silly, but I hope that won't put you off Hinz. On a more or less unrelated topic, I use my GPS for anchor watch all the time. I've got a Furuno GP-31 and it has a simple graphic page that displays a "bread crumb" trail. I find that I can see where I dropped the anchor on that screen and put a goto point there. The anchor watch alarm is then set to go off if I go outside a circle around that point. While we sit at anchor the gps continues drawing the track on the screen and pretty soon a thick arc is drawn. This makes it very easy to see if we are dragging even if it is pitch black and raining as it so often is when a front passes by in the night... After reading other posts citing an apparent lack of precision in GPS positions (probably related to weak signal strength in a forest), I decided to do an experiment to determine GPS precision with a modern WAAS-enabled GPS chip set. Hardwa Prototype board from an oceanographic data buoy using a UBLOX TIM-4A gps module. (12-channel receiver, WAAS enabled) Data was stored on SD card on the board. GPS signals were received using an outdoor antenna with a 25-foot cable connected to in indoor GPS reradiator The GPS antenna connected to the UBLOX module was about 1ft. from the reradiator. A Garmin GPSMAP 76C placed near the UBlox antenna showed 8 satellites in view with near maximum signal strentgh on 6 out of the 8 satellites. At that time the indicated precision on the GPSMAP 76C was about 10 feet. Setup: GPS data was collected at 1-minute intervals for about 23 hours starting at 1816Z 27 Oct. 2007. The data point collected was the most recent of the 1Hz NMEA outputs from the GPS module. The data was NOT averaged over the 1-minute interval. Data Processing: The collected minutes North and Minutes East were each averaged. Degrees North was 44 and Degrees East was 123 for all data points. The difference between each data point and the appropriate average was computed for each minutes North and minutes East point. The distances North and East of the average position were computed using the relationships that 1 minute of latitude equals 1 nautical mile and 1 nautical mile = 6000 feet. The distances East or West of the average position were corrected by multiplying the difference in degrees times the cosine of the latitude. I believe the overall systematic errors in this approach are less than a few tenths of a foot for each data point. Once the North and East positions were calculated, the distance of each point from the average position was calculated using d = sqrt(PN * PN + PE * PE). (All calculations were done using an Excel spreadsheet). The position errors were then examined to see what percentage of the positions fell within a specified distance from the average position. Results: Maximum Position Error: 32.0 feet. Average Position Error: 9.6 feet. Percentage with error 10ft 60.2% Percentage with error 15ft 83.9% Percentage with error 20ft 96.4% Percentage with error 25ft 99.5% Percentage with error 30ft 100.0% (1366 out of 1367) Conclusions: 1. With a modern GPS and a well-placed antenna, GPS precision should not be a limiting factor for anchor alarms if you are in an area with good WAAS corrections. You can find some information about the precision increase with WAAS he http://gpsinformation.net/exe/waas.html 2. Anchor alarm radius has to account for swinging to the anchor in normal winds and for the possibility that the winds or tidal currents may set your boat all the way to the other side of the anchor. These factors may limit the usefulness of anchor alarms in smaller anchorages or tight quarters. 3. Waking to the alarm with a wind or tide change is probably preferable to setting the alarm radius so large it will accomodate such changes. 4. GPS anchor alarms tell you nothing about the position of other boats in the anchorage. In fairly calm conditions, boats may respond differently to the combination of wind and current. Bumps, thumps and curses can ensue! Mark Borgerson |
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