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10-10-2012, 09:03
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#286
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cruiser
Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
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Re: sailboats can injure and kill
Quote:
Originally Posted by Dockhead
Most boats will be enough faster on a broad reach that they will make faster VMG to destination by sailing as you describe.
But it also depends on how much wind you have. If it's blowing hard enough to hit (or exceed) hullspeed DDW with just the headsail out, then on the contrary it will be faster to sail DDW. Depending on the sea state, you might get some surfing going, too, which can be more comfortable than quartering seas on a broad reach, depending of course on how stable your boat is and how effective the rudder is. I love sailing downwind in a good, strong wind -- say, 25 or 30 knots. The more the better -- up to the point where the sea state starts to become dangerous. In 40 knots of wind I can usually make 11 or 12 knots of boatspeed downwind, so the apparent wind is only say 28. It's a great ride; some of my favorite sailing.
In lighter winds DDW sucks on any boat -- slow and rolly and hard to manage. In less than say 18 knots of wind true, sailing downwind, I will usually go wing-on-wing in my boat, and wish again that I had bought that carbon whisker pole, but broad reaching and gybing is also an option, which becomes increasingly attractive the lighter the wind is. In less than 10 knots, however, I don't bother sailing downwind at all in my boat -- on goes the iron topsail. It takes more than 10 knots of wind to move 25 tons of my boat downwind without a spinnaker.
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Yes, i've done that -- I have a big headsail -- and she's very stable that way -- IF the waters are stable. If the waters are confused, she is confused.
I found out the hard way that it's a very BAD idea in confused, shallow waters. IN the channel going into Manatee River, sailing that way in confused waters (wind shift against the waves surrounded by shallows) -- with a close fetch, the seas parted under the stern of my boat and it dropped hard enough to bend the rudder. As I said in another post, the channel in the Manatee River isn't all that deep.
The NEW rudder.
If it had been the OLD rudder it would have broken off, and there we would have been in a bad place with no way to steer -- I could be wrong, but I don't think dragging stuff off the stern would have worked in those circumstances although we would have had to try it. Fortunately my sailing partner was very strong and was able to muscle the wheel enough to get us into the anchorage across from De Soto Point.
We were not at the ENTRANCE to the river, and not where we should not have been (in theory, anyway).
I will sail that way in the future -- in deeper water.
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10-10-2012, 09:05
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#287
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cruiser
Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
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Re: sailboats can injure and kill
Quote:
Originally Posted by minaret
Hmmm. Basic physics- "The shortest distance between two points is a straight line".
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That would be 100% accurate if there was only one force acting on the boat and if all boats were identical. That's "too basic physics."
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10-10-2012, 09:08
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#288
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Registered User
Join Date: Mar 2008
Location: Calgary, AB, Canada
Posts: 6,252
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Re: sailboats can injure and kill
Quote:
Originally Posted by minaret
Hmmm. Basic physics- "The shortest distance between two points is a straight line".
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However, on almost any polar diagram (and in reality) the slowest point of sail is DDW.
__________________
CRYA Yachtmaster Ocean Instructor Evaluator, Sail
IYT Yachtmaster Coastal Instructor
As I sail, I praise God, and care not. (Luke Foxe)
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10-10-2012, 09:24
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#289
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cruiser
Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
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Re: sailboats can injure and kill
Quote:
Originally Posted by jackdale
However, on almost any polar diagram (and in reality) the slowest point of sail is DDW.
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Sure. As others have pointed out, you have to choose your point of sail carefully. The extra speed has to have more effect on the length of your trip than the extra distance.
Then you have to consider your boat, and comfort as well as safety counts. My boat has a big, fat stern. That might have a significant effect in a heavy following sea.
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10-10-2012, 09:25
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#290
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Senior Cruiser
Join Date: Oct 2008
Location: Coos Bay, Oregon
Boat: Valiant 40 (1975)
Posts: 4,073
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Re: sailboats can injure and kill
Quote:
Originally Posted by Rakuflames
Yes, i've done that -- I have a big headsail -- and she's very stable that way -- IF the waters are stable. If the waters are confused, she is confused.
I found out the hard way that it's a very BAD idea in confused, shallow waters. IN the channel going into Manatee River, sailing that way in confused waters (wind shift against the waves surrounded by shallows) -- with a close fetch, the seas parted under the stern of my boat and it dropped hard enough to bend the rudder. As I said in another post, the channel in the Manatee River isn't all that deep.
The NEW rudder.
If it had been the OLD rudder it would have broken off, and there we would have been in a bad place with no way to steer -- I could be wrong, but I don't think dragging stuff off the stern would have worked in those circumstances although we would have had to try it. Fortunately my sailing partner was very strong and was able to muscle the wheel enough to get us into the anchorage across from De Soto Point.
We were not at the ENTRANCE to the river, and not where we should not have been (in theory, anyway).
I will sail that way in the future -- in deeper water.
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That is funny Raku- I have been in the exact same spot and got stuck in the sand. It seems like the sand in that channel is aways changing and never where it should be on the chart. I can't imagine it in confused seas- that would have been a nightmare. We were just trying to get up to the marina with the er.. pool at dockside.
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10-10-2012, 09:27
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#291
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Resin Head
Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
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Re: sailboats can injure and kill
Quote:
Originally Posted by Therapy
Yea, but that is just distance.
rate x time = distance.
rate makes a difference too.
could somone do the math for me please?
In a boat I no longer have;
8 knots true wind.
DDW, 4 knots.
150°, 6 knots.
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We were not discussing time here, strictly distance. Dockhead said the distance is the same regardless of whether you gybe daily or sail DDW. I don't get that. Obviously since we were discussing sailing long blue water passages on trade wind routes, the intended course is DDW.
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10-10-2012, 09:32
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#292
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Resin Head
Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
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Re: sailboats can injure and kill
Quote:
Originally Posted by jackdale
However, on almost any polar diagram (and in reality) the slowest point of sail is DDW.
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Does no one read all the previous posts? We already said that DDW may be slower (in some boats), but it's less miles sailed with less stress on the gear. That's the whole point, less apparent wind for similar speed. And less work for crew and boat.
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10-10-2012, 09:34
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#293
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cruiser
Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
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Re: sailboats can injure and kill
Quote:
Originally Posted by s/v Beth
That is funny Raku- I have been in the exact same spot and got stuck in the sand. It seems like the sand in that channel is aways changing and never where it should be on the chart. I can't imagine it in confused seas- that would have been a nightmare. We were just trying to get up to the marina with the er.. pool at dockside.
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The effects of the Gulf can go pretty far up that river because the mouth is so broad.
I didn't tell the whole story. First the keel skipped along the bottom. My friend looked at me and said "What was that?" He's done a lot of racing, but in deep water.
I said, "The keel skipped across the bottom. We have to get over more to the south side of the channel." (For the person sailing to Caya Costa, that's virtually always the deeper side of the channel if leaving the Gulf in this part of Florida).
The second time the boat really THUNKED into the sand and stopped. I said "Don't worry, the next wave will lift us off" -- and they were coming fast.
It did get us off -- right before it dropped my ass hard on the bottom.
I will never take this boat through confused water without looking at the tide chart again. My boat is vulnerable, and that's just how it is. I'll turn around, go out into the Gulf, and heave to until the water is deeper. Since I'm moving to the Manatee River I need to think about that.
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10-10-2012, 09:35
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#294
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Registered User
Join Date: Mar 2008
Location: Calgary, AB, Canada
Posts: 6,252
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Re: sailboats can injure and kill
Quote:
Originally Posted by minaret
Does no one read all the previous posts? We already said that DDW may be slower (in some boats), but it's less miles sailed with less stress on the gear. That's the whole point, less apparent wind for similar speed. And less work for crew and boat.
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I find DDW is more stressful on the crew; it requires much more attention.
How is a broad reach more stressful on the gear?
__________________
CRYA Yachtmaster Ocean Instructor Evaluator, Sail
IYT Yachtmaster Coastal Instructor
As I sail, I praise God, and care not. (Luke Foxe)
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10-10-2012, 09:37
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#295
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Resin Head
Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
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Re: sailboats can injure and kill
Quote:
Originally Posted by jackdale
I find DDW is more stressful on the crew; it requires much more attention.
How is a broad reach more stressful on the gear?
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Again, read the earlier posts. We already had this argument.
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10-10-2012, 09:39
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#296
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cruiser
Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
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Re: sailboats can injure and kill
Quote:
Originally Posted by jackdale
I find DDW is more stressful on the crew; it requires much more attention.
How is a broad reach more stressful on the gear?
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If it's close to DDW, unexpected gybe, 'cuz the boom will really be out there.
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10-10-2012, 09:48
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#297
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Registered User
Join Date: Mar 2008
Location: Calgary, AB, Canada
Posts: 6,252
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Re: sailboats can injure and kill
Quote:
Originally Posted by Rakuflames
If it's close to DDW, unexpected gybe, 'cuz the boom will really be out there.
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I was asking how a broad reach is more stressful than DDW.
You are more likely to get an accidental gybe while DDW. On a broad reach the headsail collapses when you get too far downwind as the mainsail blankets the headsail. That is a clear indication that you need to head up. I teach my students to pay some attention to the clew of the headsail when broad reaching ; when it drops, head up slightly.
__________________
CRYA Yachtmaster Ocean Instructor Evaluator, Sail
IYT Yachtmaster Coastal Instructor
As I sail, I praise God, and care not. (Luke Foxe)
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10-10-2012, 09:49
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#298
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CF Adviser
Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
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Re: sailboats can injure and kill
Quote:
Originally Posted by Therapy
could somone do the math for me please?
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it's fairly easy trigonometry: speed over ground times the cosine of the true wind angle.
__________________
cruising is entirely about showing up--in boat shoes.
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10-10-2012, 09:49
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#299
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cruiser
Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
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Re: sailboats can injure and kill
Quote:
Originally Posted by minaret
We were not discussing time here, strictly distance. Dockhead said the distance is the same regardless of whether you gybe daily or sail DDW. I don't get that. Obviously since we were discussing sailing long blue water passages on trade wind routes, the intended course is DDW.
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Well, no. YOU were talking strictly distance. And, he did not say the distance was the same. He said the time *could* be the same. I pointed out that my friend won those races using gybes by picking his points of sail very carefully.
By the way (not directed to Minaret), that same friend bent his rudder the same way I did, except that he was in the channel in Sarasota Bay.
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10-10-2012, 09:56
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#300
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Registered User
Join Date: Jul 2007
Location: W Florida
Boat: Still have the 33yo Jon boat. But now a CATAMARAN. Nice little 18' Bay Cat.
Posts: 7,083
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Re: sailboats can injure and kill
Quote:
Originally Posted by minaret
We were not discussing time here, strictly distance. Dockhead said the distance is the same regardless of whether you gybe daily or sail DDW. I don't get that. Obviously since we were discussing sailing long blue water passages on trade wind routes, the intended course is DDW.
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Oh, I think he just misspoke.
__________________
Who knows what is next.
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