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Old 08 December 2008, 03:56   #21
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Originally Posted by chewy View Post
At the end of the day its upto the individual but I personally would deploy the sea anchor.
Do you carry one? we have a Drogue on board which could be deployed as a sea anchor just we have never tried it. However I don't think it has to be anything special, a bucket or pair of sailing salopettes could be used.

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Can anyone explain how filling the boat with water actually stops the boat from been beam onto the sea?
I don't think it does, I think flooding the hull is more about increasing stability and reducing the possibility of a breaking wave capsizing the rib. Alan does explain it in his first book. those interested in reading more about his idea perhaps should look on Amazon for a copy.

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Old 08 December 2008, 04:50   #22
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I never said it was bad advice Alan. What I do know is that a boat with no sea anchor will get washed up the beach and one with a sea anchor deployed will ride the waves, it will probably end up on the beach but will have given the crew chance to fix things.

I've just bought a sea anchor for my SR, it not been in the water yet due to it been refurbed.

I've used sea anchors loads of times on the Atlantics and they work. Why do the RNLI fit them? If you capsize you deploy the sea anchor so when the boat rights again its facing the weather so it doesn't go over again.

I'm sure in the sort of RIBs you use Alan your method works but I'd prefer to ride it out facing the weather rather than just bobbing and surfing all over the place.
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Old 08 December 2008, 05:36   #23
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Better still, dont use it. We worked a long time on establish if a sea anchor would work in big seas and the boat ended up being safer without. I would always advocate filling the boat with water if you cannot make headway in big seas or are drifting on to a lee shore.
Not quite the "RYA" way but then again, have they ever had to survive in bad conditions
If I read this right you are saying you would prefer to allow your boat to blown beam on and be full of water in bad condition when trying to keep of a lee shore.

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Until the tubes come off, my 6.3 Ocean Pro holds 5 tonnes of water! Personally I like the water not in the boat.
Call me old fashioned but I think I would agree with Jono on this one

Lesson 101 in capsizing a boat (not making way).

As a general rule itís a breaking wave that will capsize the boat. As a rule of thumb it is fairly well accepted that a beam on breaking waves thatís height is equal to the beam of your vessel may capsize you, bigger than that more likely. Itís also generally accepted that if you are bow to the waves the breaking wave will need to be over 80% of the boats length to capsize you.

Do the sums and we can see pretty clearly that any techniques that hold the bow to the waves are likely to prevail over a technique that allows the boat to be beam on to the same breaking waves.

The sea anchor does just that, deployed from the bow it avoids you becoming beam on, given a long enough line it also increase the 80% margin quite considerably as it provides some resistance for the bow.

The RNLI I believe fit a sea anchor as standard on their Atlantics- I have certainly seen a few clips where quick deployment was the one factor that saved the boat from impending disaster.

We have spent considerable time experimenting with sea anchors, although much of it has been from larger racing yachts. On the two occasions we did it from a 7m ish RIB in rough weather the sea anchor was not sufficient to hold the bow to sea/wind, my conclusion was simply the sea anchor on the boat was not big enough for the boat. It was in fact the same as the sea anchors that come with a standard SOLAS life raft. The life raft of course has the benefit of ballast bags which the RIB does not.

I have also spent time with my boat full of water, however this was never intentional, as already mentioned there are issues of electrics, fuel tank breathers, hypothermia etc, however to my mind filling the boat with water kind of defeats the objective of having a boat in the first place. I hope I never get into a situation where my mind remembers this thread and start to wonder if it is the appropriate action.
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Old 08 December 2008, 07:00   #24
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At last someone sees sense rather than just agreeing.

Indeed all Atlantics are fitted with sea anchors and are permanently fitted in the bow, they can be deployed from the stern in the eent of a capsize.
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Old 08 December 2008, 07:12   #25
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All.

Whilst I accept that there are always training manuals and courses for this, there are times when the conditions and situations are so bad the "Written Rules" will not work.

Here is the simple version of why I would always advocate filling a boat with water. By flooding the hull, the displacement will go below the waterline and the craft will become part of the sea and rise up and down with each wave or breaking wave. Holding the bow into big seas in a small boat can cause more problems than expected, ie the wave will roll over the bow and in some cases pitchpole the entire craft and crew. On a lee shore the craft should rise up and down over the hazards of rocks etc and get you closer to shore so you have a better chance of not being smashed to pieces on the rocks. Of course the boat is a total write off but you and the crew should live to tell the tale.

It has to accepted that unless you have tried any of this in BIG seas, comments can only be made from courses that you have attended and books you have read.

So here is my experiance of bad weather over the past few years

RIBS

1997. 7.4 metre rib, North Atlantic coming back from USA via Greenland 55 knots lying a hull for 12 hours.
2000 10 metre rib 50 miles NW of Ireland 45 knots lying a hull for 20 hours.
2001 10 metre boat, 1000 miles off Canada Coming from New York to UK, 50 knots of wind and three converging storms (Hell) lying a hull for 15 hours.
2002 10 metre Rib 70 knots in the South China Seas 18 hours.
2002 10 metre rib 120 knots in Hurricaine Hannah, Canada. We went out for a play to see what would happen. After this I gave the sea anchor and drouge to The Royal Newfoundland Yacht Club to auction for charity as it was a waste of time to carry it..
2003 10 Metre rib 77 knots off the tip of Greenland 8 hours.
And we lived to tell the tale so in this case, there is a very good reason for flooding the hull.
I guess that one of the main things is to make sure your craft is built right in the first place and all the electrics are waterproofed. The other alternative is to look at the wetaher forecast and not go out in it!

Sailing

2006 Lively Lady 36 foot sailing yacht 50 knots North Atlantic 48 hours bare poled.
2006 Lively Lady 55 knots South Carolina 12 hours.
2007 Lively Lady 70 knots Wilsons promitary Australia. ( this is the area that the Sydney Hobart went all wrong.

The rest really doesnt matter but as I said earlier, What do I know? Everything that the skipper does has to be down to his skills and past experiances. I have sailed with many good skippers who have got in to lots of trouble by "Sailing by the Book"

Only experiance will teach you lessons

Alan P
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Old 08 December 2008, 07:19   #26
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Hey, what do I know?????????????????
AS for bad advice, Before you all knock what I am saying, wait for a really bad day and try it.
A fully water logged boat of any discripton is better than something sitting on top of the water in any conditions.
Alan P
I have no idea what you do know and what you don't know.

However your statement above is nonsense. "A fully water logged boat of any discription (sic) is better...".
Of any description? Many boats would break up far more easily in rough seas when water logged rather than if fully buoyant and riding the waves.
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Old 08 December 2008, 07:33   #27
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Tim - I think you need to put this into context - Alan has far more experiance than most of us. If there were me & him in a boat & its was all going tits up - I'd let him make the call on the best course of action every time.

Part of being a decent skipper is knowning when to learn from others experiance/ mistakes / whatever you want to call it.

In this case its not bouyancy thats in disput - its stablity / risk of capsize & being blown onto a lee shore. A fully bouyant rib has bugger all under the water & will be blown very quickly . Put a couple of tonnes of water in it & it takes a lot more wind to move it the same speed/ distance . Likewise a wave will flip a light boat far easier than a heavy one with the weight at the bottom - just look at yachts - its why they have a bloody great big weight hanging under them .
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Old 08 December 2008, 07:38   #28
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Cheers Alan. How do the RIBs lie without any drogue and full of water?
Do you intentionally fill the RIB with water or just let nature take its course.
We can't fill the Atlantics due to the open transom.
Do you get problems with the engine with the boat sitting so much lower in the water, ie water ingress through exhaust etc?
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Old 08 December 2008, 09:42   #29
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Chewy. in my experiance, they lie fine, I am here to tell you about it so that must mean something. We leave the scuppers down and nature does the rest.
Our engine boxes are always water tight and the breathers at the highest possible point. As a rule, outboards are pretty much water tight and dont present too many problems that a good can of WD40 wont sort out.
Timw.
Outside water pressure against inside water pressure = Zero so why should it break up unless it was a piece of crap in the first place? As I said, there is no subsitute for a well prepaired craft and half a million sea miles and every ocean does give me the edge over a lot of people. The other thing to take into consideration on a lee shore is once you ruduce the windage, the current runs up and down most coastlines which will give you a better chance of survival. Again, I am talking about conditions that the rescue services would find it difficult to help you with apart from above.
The RIBNET Forum is here for people to ask advice and for others to pass it on. I only speak from experiance, if it is to be disregared, so be it and in the unfortunate event of a mishap you must make your own mind up as to how you deal with it, We all have our own lives to live and although I am sure that I have used up more than my fair share of mine, I am still here.
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Old 08 December 2008, 10:26   #30
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Thanks Alan, its good to hear other people expeirences and methods.
Not sure if I should block the flooding hull on my SR up now!
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