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Old 12-01-2004, 20:16   #1
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Lying Ahull

In a book I have, "Heavy Weather Sailing"-by K. Adlard Coles, there's some interesting comments on lying a hull.

Lying a-hull - Taking off all sail,lashing the helm-usually slightly to leeward,closing all hatches securely and letting nature take her course.

From the jest of it, this is my understanding on some of the comments from the book.

Broadly speaking, old fashioned narrow beam heavy displacement yachts often lie a-hull well,wilst light displacement beamy yachts do not.

Even so, lying a-hull was the most popular storm tactic used during the 1979 Fastnet race, which was filled with light displacement race boats.Many boats survived,even after their crews had been rescued from the boats.

In a sufficient force of windage,the mast alone provides stability,like a steadying sail.However, lying a-hull does make a boat vulnerable to breaking waves from broadside on, possibly rolling the boat over.

Several notable circumnavigators- Sir Alec Rose,Dr.Nicholas Davies,and Alan and Kathy Webb, consider the practice of lying-a hull satisfactory for weathering the gales of normal world circumnavigation,while sailing heavy displacement boats.

If you were considering a circumnavigation, which type of boat would you prefer? A narrow heavy displacement vessel, or a light displacement beamy vessel? Obviously, there is a trade-off here. Stability vs.speed. What do you think?
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Old 13-01-2004, 01:32   #2
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Submarine-ing

Personally, I wouldn't like lying a-hull. The thought of broaching and a roll over could ruin my whole day.
I would prefer a vessel that could take the waves head on. A sea anchor would be my choice unless the wind was off from the waves, which is not very common. Then I'd be at the helm.
From what I've read every storm is a little different. The choice would have to be made for what ever vessel you choose for other reasons. I think, getting to know your ship and what it can handle is the best choice. And of course a quality ship as well!

Sail on..........................._/)
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Old 13-01-2004, 05:47   #3
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I've never practiced lying a-hull, but then again,I've never been in true open ocean during a ferocious gale.I've been in some pretty nasty stuff, but usually I will heave-to if possible,or just stay at the helm and motor,keeping some headway.

In my mind, lying a-hull is a last ditch tactic.The conditions have become so bad,that crew can't stay on deck safely,and wind velocity is to severe for heaving-to.

I've never used a sea anchor either.I understand the principle of the device, but have just never been in a situation that I felt one would help me. I always thought that when I head off to cruise full time, I would have one aboard and be familiar with how to properly launch,and retrieve it.However, as I mentioned once before on this board,I ran across a blue water sailor that has me re-thinking the use of sea anchors.He said in a true Gale, the forces exerted on the bow section of a boat while using a sea anchor are usually greater than what the design of the boat can with stand. This blue water, sailing class instructor, said he had seen numerous boats damaged from using sea anchors.One of which,had a partial removal of the bow.The sailor I'm mentioning had a 40ft.Pacific Seacraft Cutter that had also substained some damage from using a sea anchor. He had no problem with the use of drogues, just sea anchors.With all that said, it's my intention to talk with more blue water sailors concerning the use of sea anchors.

IMO, the best heavy weather tactics are in this order:

*** Staying at the helm under reduced sail,i.e-reefed main (or no main) and a storm sail. A good helmsman can do a lot to maintain the safety of the boat by avoiding breaking waves and putting the boat in the position of being broached.

***Heaving to - The tactic can be very useful in reducing physical stress on both the boat,and crew.

*** Lying a-hull - Last resort. Good chance the boat will be rolled,and possibly dismasted.

When I read the information in my book concerning the authors opinion that narrow, beamed heavy displacement boats are better suited for lying a-hull, it made me think of the movie "A Perfect Storm." If my memory serves me correctly, the small sailboat that was caught out in the storm was a Westsail 32. The Captain originally tried to heave-to under a storm sail, but ultimately had to lie a-hull. Even though the crew eventually abandoned ship (against the Captain's will) the boat was later found washed ashore on a beach, virtually unscathed.
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Old 13-01-2004, 21:42   #4
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I wonder if some of the problems experienced by these sailors were due to the line to the sea anchor being too short or positioned incorrectly. 300-500 feet is often recommended. The length has to be adjusted so that the anchor and boat are in the crests and troughs at the same time. The elasticity of the long nylon line also eases the load.
In my mind sea anchors while okay for monohulls work even better with multihulls due to the bridle effect of the wide beam. Same goes for drogues, you get better control with a widely spaced bridle.
I always thought lying ahull is okay as long as the waves are not breaking. My tri will slide sideways when hit from the side by smaller breaking waves while lying ahull. But I would not do this in extreme conditions with large breaking waves.
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Old 14-01-2004, 05:34   #5
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Steve,

Your questions concerning the length and type of scope that was being used while these boats suffered damage from the use of a sea anchor, are right in line with mine.When the instructor mentioned this during the class I was intending,I wanted to discuss it further, but we had a lot of material to go over at the time,and he quickly moved on.

As I mentioned, my intention is to talk with many other blue water sailors concerning the use of sea anchors before I form my opinion on them.
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Old 14-01-2004, 06:32   #6
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As you note, lying a hull is a last ditch solution. Heaving to is a much more effective solution. (For the record, the Westsail 32 that was abandoned in "The Perfect Storm' was abandoned hove to under storm jib and Storm trisail.) I think that you are mistaken in saying that "old fashioned narrow beam heavy displacement yachts often lie a-hull well,wilst light displacement beamy yachts do not." I think that is an oversimplification. The problem encountered by the Fastnet disaster boats was not that they were light displacement but that they were IOR era boats that have very high vertical centers of gravitym were heavily dependent on form stability and crew weight on the rail, and had extreme beam and flair. While modern boat theory has diverged into two camps, the design theory based on the IMS typeform and Volvo typeform, produces boats that are not overly wide, are not heavily dependent on form stability, and have very low vertical centers of gravity. Boats like these actually have a very good chance of suviving when lying under bare poles with the helm down. I think that the Sydney Hobart report is very telling because here were more experienced crews sailing a mixture of older traditional and IOR boats, as well as, IMS typeform boats. The largest loss of life was on 'Winston Churchill' a traditional heavy displacement cruiser/racer that was picked up by a wave and thrown upside down.

It should be noted that boats of these typeforms did extremely well in the Sydney Hobart disaster while older types, both racing and cruising during that storm did pretty poorly. Also, it should be remembered that one of the casualties of the storm that caused the Fastnet Disaster was a Westsail 32 that was rolled losing its rig and then later lost its rudder while riding to a drogue of some kind. When you talk about that kind of heavy weather you need to realize that there is no 'magic bullet' that will always keep you safe.

Jeff
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Old 14-01-2004, 07:35   #7
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The comments I made concerning lying a-hull were taken from the book "Heavy Weather Sailing", by K.Adlard Coles, which I referred to.

As far as the sailing vessel "Satori" (sailboat mentioned in the book "The Perfect Storm", below is an account of the incident from the Captains perspective. Interesting stuff.....

http://world.std.com/~kent/satori/Na...tml#LyingAhull
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Old 14-01-2004, 12:03   #8
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Good reading that article is.

All the expenses to owner and danger to rescue crew just becuase some women panicked.

Makes one think twice bout taking on crew.

Did not know that one could loose captain licence and documentation by refusing evacuation.

That true..?
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Old 14-01-2004, 14:20   #9
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Hi CSYman,

Yep, women...you can't live with them,and you can't live without them

As far as the refusal to evacuate order - I was unaware of that also. I asked a buddy of mine that has some USCG ties, and this is the way he explained it to me.

On my license, I'm listed as a "U.S.Merchant Marine Officer." As such, I'm under the commandement of the USCG.If I were to refuse a direct "order" from them, there would be a hearing concerning the incident,and yes I could loose my license,and documentation. They be de man!
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Old 14-01-2004, 18:09   #10
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I have read that account as well. There was another online account by the women and corpsman that somewhat supports the version of the Satori incident in the book and says that this was something of an after the fact in the cool light of day telling of the story. (I just did an online search and could not locate it) I wasn't there so I am not making any assumptions here.

Jeff
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Old 14-01-2004, 19:41   #11
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Stede:

Yes, my license also says US Merchant Marine Officer, and Master.

Therefore I thought I could use the judgement my genes gave me to detemine who needs to get off my ship..

That is my version and I will stick to it.

Going sailing to the Bahamas tomorrow..Good life.
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Old 14-01-2004, 19:45   #12
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boat design

Quote: "Lying ahull is a well-established technique for sailing in heavy weather offshore. It involves taking down all sail, lashing the helm, and staying secure below. The boat will lie beam to the waves and will roll. If the amounts of windage and drag (from the keel) are right, the boat will slip sideways through the water, giving way before the waves. Too much keel and the boat will get caught in the waves and tend toward knockdowns. Too little keel or too much windage and she will move too quickly across the surface. It's also important to balance the forces for and aft lest the vessel get driven stern first, as that can damage the rudder. "

Obviously, lying ahull is not for my vessel with a deep fin keel and a spade rudder. Before lying ahull I would want a boat proven in the conditions.

As for the sea anchor, there are different sea anchors for each vessel. One too large and/or too short of line would put too much stress on the vessel.

http://store.yahoo.com/landfallnav/s...rsdrogues.html

This is a good thread, one needs to know all the options for ones vessel.
It's understandable why sailors of the old days considered woman on ship, bad luck. With that, it's time to run.............._/)
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Old 14-01-2004, 20:45   #13
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I enjoyed the account of the Westsail 32 owner. I would be hopping mad if that happened to me. As for letting the boat go beam on I do not agree with that. This is just theory cause I have not tried, but I think I would prefer to have the stern of the boat facing the waves. The reason is I do not like the idea of the pointy end facing the waves because of the strain on the rudder going backwards and the boat is not really designed to go backwards. So I would like to go the correct way around with the brakes on if required. One of the sailors in the Sydney Hobart race mentioned attaching the sea anchor rope at midships so the transom would not be held down as a wave passes underneath. I have built my own sea anchor and can advise on the construction if anyone is interested. A good use for them is fishing with a fresh breeze behind, you can adjust the trolling speed.
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Old 14-01-2004, 21:41   #14
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The reason for a sea anchor (S A) is to keep the bow into the wind and waves. A backwards motion would only be what the sea anchor allows, hopefully being the proper S A for the vessel. Having the transom to the flow with a S A would probably flood the cockpit and anything else down stream. A breaker over the transom could be disasterous. And I'd think that would put even more stress on the rudder.

If the wind and waves were at an angle to each other, a line off the P/S side bow could keep the bow in to wind or waves, which ever would be less stressful on the hull.

S A's are just like any other peice of equipment. One has to gain some experience and learn how they work in different situations.
There are experts out ther that can design the proper S A's and give instructions on their use. A few trial runs on a stormy day would be to one's advantage when the big one comes along.

>>>>>>.......,.,..,.,.,._/))~~~~~~

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Old 15-01-2004, 05:49   #15
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I want to touch on something that Delmarrey said above: "Obviously, lying ahull is not for my vessel with a deep fin keel and a spade rudder. Before lying ahull I would want a boat proven in the conditions."

Based on actual practice, the newer fin keel/ spade rudder boats lie a hull pretty nicely. Coles book is a little outdated on things like this. When lying ahull there is minimal foreward motion so the keel is perpendicular to the water flow. In that flow direction fins tend to stall which is actually what you want to prevent the knock downs that Coles refers to.

In the studies of actual knockdowns and in the tank testing that was used to develop the EU's STIX (stability index) standards, fin keels were found to do quite well. The caviat here is that many older IOR era fin keelers have a very high VCG and were prone to knock downs because of that rather than their keel confurations. Newer designs of the IMS typeform have very low VCG's and comparatively small area and large aspect ratio foils, and so do much better than traditional typeforms when it comes to this kind of thing.

So while Delmarrey's boat may not be able to lie to it is not because of its fin keel and spade rudder but because of its high VCG.

Respectfully,
Jeff
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