Parachute sea anchor

[serini]

Second or Fifth and Bridle

Well, that is an eye opener! Actually it is the Third edition I have of 'Heavy Weather Sailing'.

The Pardeys promote using a bridle - sea anchor streamed from the bow with a block running on that line tied on to a separate line taken aft to something like a sheet winch. Adjusting the strain on that second line then adjusts the angle to the seas so that they can be taken at something like 30 degrees (if I recall - I haven't checked).

That is all of course supposing that your boat lies bow-to to start off with which may require the use of some sail well aft.

 

[Deleted member 36384]

James Wharram, the Catamaran designer and builder, suggests the bridle rigged much like prv's recollections of the Pardeye's instructions. Wharram commented that digging the stern in, with a sea anchor deployed from the bow only, risks capsizing by pitch pole on a breaking wave. Presenting the boat at an angle offered more buoyant area which would increase lift. He also commented, as has been mentioned by Ceirwan, that the drift slick of the boat induced the wave to break up drift of the yacht. I understand that this is a key feature of the acute angle approach, the drift slick protecting the yacht.

His comments, I think, can be found in his design manual, which might be available on the web, or his web site. He backed up his discussions with examples from Wharram sailors. Indeed, in keeping with Wharram's style, he suggested that even a couple of car tyres would help produce the same effect.

 

[fishermantwo]

I started this thread following a comment which had been made about Jeanne's knockdown. She reports that she had hove-to. There is a subsequent mention of her series drogue being fouled by a fishing boat so that may - or may not - have been deployed at the time of her knock down. A very, very experienced acquaintance of mine said he was not surprised at the knock down and 'Adlard Coles would turn in his grave' so I read the posts again and could not see much wrong with her heaving to under the conditions reported unless she ended up broadside on (so effectively ahull) and the hull tripped. Or unless of course if there was just simply a freak wave with her name on it. Anybody else got another take on this?

Thanks to you all for your posts.

I made a comment on a previous thread about the fishermen who allegedly cut off the towed series drogue and had my head bitten off.

I'm fairly sure that the problem people are being confused by is the way Jeanne described the incident in her blog. Jeanne mentions being hove too and then shortly afterwards talks about hanging off a series drogue. I'm thinking maybe she hove too but found that unsatisfactory. Then lowered all sail and lay a hull and then went to a towed series drogue running off downwind. Eventually we may get a better description of events and draw conclusions that we all can benefit from.

 

[westernman]

James Wharram, the Catamaran designer and builder, suggests the bridle rigged much like prv's recollections of the Pardeye's instructions. Wharram commented that digging the stern in, with a sea anchor deployed from the bow only, risks capsizing by pitch pole on a breaking wave. Presenting the boat at an angle offered more buoyant area which would increase lift.

Interesting. There is this article http://www.timesonline.co.uk/tol/news/uk/article7111417.ece which suggests that the largish cruising cat in the article capsized in the med because the sea anchor was deployed unsymmetrically. Unfortunately with fatalities.

I don't know the answer - the most I have experienced is a F9 in the med and I can confirm that it is definitely more pleasant running before it rather than hove to or heading into it. But it may well be very different in a F10 or F11. I hope not to have to find out.

Please keep this interesting thread going.

 

[Kelpie]

I've only read two editions of Heavy Weather Sailing, the 2nd, and the 5th. One thing I really did notice was the difference in opinion between the two. In the second edition all the advice seemed to point at either streaming warps or towing drogues and running before the storm. Where as the 5th edition seemed to promote the use of sea anchors as a much preferable tactic. Something I'm sure to do with how boat design had changed between the two publications, rather than the effectiveness of either method.

That's interesting. Perhaps you could say that modern boats are shaped more like dinghies, and we know that sea anchors are a viable survival option for them. Coincidence?

 

[Woodlouse]

That's interesting. Perhaps you could say that modern boats are shaped more like dinghies, and we know that sea anchors are a viable survival option for them. Coincidence?

Quite, the light, shallow form of a modern plastic boat is rather dinghy like with the exception of the ballast keel. Where as the heavy, deep hulls of older designs represent a completely different set of characteristics, and so both types require different approaches to heavy weather. Of course, you'll never truly know what's best for your particular boat until you've experienced it.

 

[serini]

Jeanne

I made a comment on a previous thread about the fishermen who allegedly cut off the towed series drogue and had my head bitten off.

I'm fairly sure that the problem people are being confused by is the way Jeanne described the incident in her blog. Jeanne mentions being hove too and then shortly afterwards talks about hanging off a series drogue. I'm thinking maybe she hove too but found that unsatisfactory. Then lowered all sail and lay a hull and then went to a towed series drogue running off downwind. Eventually we may get a better description of events and draw conclusions that we all can benefit from.

Second all of that. Of course for Jeanne what is topmost in her mind at the moment is her repairs and getting them done before winter closes in on her. I have sailed down there and been at the dock she is at now. The logistics of what she has to overcome now are mind boggling but then she is one smart, gutsy resourceful lady. Why did you get your head bitten off? Were you rude about the boat that stood by or something?

 

[JayBee]

The Australian Seabrake drogue has been mentioned several times in this and similar threads. The manufacturers claim that it functions both as a drag device and as a sea anchor. Does anyone have experience of using one of these in both modes?

I would imagine that, deployed as a sea anchor, it would produce much less drag than a parachute type and that a bridle type rig, as advocated by the Pardeys, might be necessary to open up the drift angle, with reduced sternway and the possibility of rudder damage.

When sailing fast downwind in a gale, without any drag devices, I have had large waves occasionally breaking into the cockpit. This usually happens with the Aries steering gear in charge and is associated with yawing in the troughs, when the wind vane is temporarily blanketed. A drag device would almost certainly improve this situation. Continuous hand steering for hours on end is never going to be an option for us.

As far as sea anchors in general are concerned, I like the idea of presenting the forepart of the boat to the sea, letting the weather system go by and not having to worry about excessive lost ground or running towards a lee shore, if there is one.

My boat is fairly heavy displacement, tiller steered, with a transom hung rudder. Unfortunately (or fortunately) I have no experience of sea anchors or drag devices in use to offer. When I was a young 3rd Mate, one of my jobs was to look after the ship's lifeboats. They were all equipped with sea anchors, with slick producing oil bag attachments.

This is a very interesting thread, but I suspect the bottom line is "whatever works for you".

 

[Tradewinds]

They were all equipped with sea anchors, with slick producing oil bag attachments.

What happened to the method of pumping oil through the toilet outlet to produce a slick effect. I think Eric Hiscock used to use this method.

Disproved, out of fashion or just forgotten by today's sailors?

 

[sighmoon]

Nathan, out of interest, do you know how bad the conditions/sea state were when Roger Taylor deployed the drouge on ming ming? I've seen his youtube video of when he had to deploy, it, and would conject that while its a blow, it's not necessarily survival conditions as depicted in a lot of other accounts.

The video you mentioned:
http://www.youtube.com/watch?v=DrTfbjnUZWY

I'd never come across it before, and very much enjoyed his series.

Something to add to the debate is that he had a very hard time getting the drogue back in when he wanted to - and that on a small boat with very low windage. Once deployed, a sea anchor or drogue might well be there until the storm has passed, so may not be a good solution for keeping off a lee shore.

 

[Woodlouse]

What happened to the method of pumping oil through the toilet outlet to produce a slick effect. I think Eric Hiscock used to use this method.

Disproved, out of fashion or just forgotten by today's sailors?

Oil has rather gone out of fashion these days but I think is probably well worth remembering. If I recall the advise from Heavy Weather sailing again it was deemed best to have an oil bag hanging off the leeward guardrails that would release a steady quantity of oil for the boat to drift down upon thereby leaving a slick to windward.

I think the RNLI still uses oil, but some form of vegetable oil, not mineral.

 

[KellysEye]

I've always susbscribed to the view that if you have a lightweight boat and spade rudder use drogues. If you have a heavy dispacement boat with the rudder attached to the keel use a parachute anchor. The reason is with a parachute anchor all boats are pushed backwards but a spade rudder is likely to break. It's a moot point what a full skeg rudder should do. Horses for courses as ever.

 

[VO5]

.....And Snowleopard has not surfaced again yet, to give us the learned hypothesis I requested. When he finally does...I will come in to bat.

 

[Sybarite]

The Pardeys advocate lying to a sea anchor but at an angle induced by taking a line to the stern. The resultant slick helps weather the conditions.

 

[westernman]

The Pardeys advocate lying to a sea anchor but at an angle induced by taking a line to the stern. The resultant slick helps weather the conditions.

Please see my previous post about a catamaran which was lost in the Med with fatalities because the sea anchor attachment was a bit off centre.

 

[Ceirwan]

Please see my previous post about a catamaran which was lost in the Med with fatalities because the sea anchor attachment was a bit off centre.

I've just finished reading the article.

It doesn't really justify that the reason was the off centre sea-parachute. He simply says thats what caused it.

The Pardeys use of a Sea-Anchor is different... in their case the yacht is hove-to which is an entirely different matter to riding to a sea anchor exclusively, its purpose is simply to prevent the yacht making forward progress and sailing out of the protective slick.
But, I'm thinking in monohull terms, a monohull would have righted itself after flipping over, I don't really know how you would handle the rough stuff in a multi hull.

 

[Lady Campanula]

.....a monohull would have righted itself after flipping over....

Another urban myth!

May I respectfully suggest you've got more reading to do.....?

 

[serini]

Pardeys Hove To?

I've just finished reading the article.


The Pardeys use of a Sea-Anchor is different... in their case the yacht is hove-to which is an entirely different matter to riding to a sea anchor exclusively, its purpose is simply to prevent the yacht making forward progress and sailing out of the protective slick.
But, I'm thinking in monohull terms, a monohull would have righted itself after flipping over, I don't really know how you would handle the rough stuff in a multi hull.

Ceirwan thanks for this. This is not my reading of the situation but I am making this comment to try and get to the heart of this debate so please do come back to me, of course I could be wrong. In this post I am not considering Cats.

I started this thread to try and understand what I saw as discrepancy between tactics advocated by Coles/Bruce and the Pardeys. It seemed to me that the sea anchor off the bow even when modified by a bridle had the great potential disadvantage of the boat being driven back on her rudder. I feel sure that would be the weakness in my own boat and, to date, I have always been able to run off.

I don't see the Pardey approach as "prevent the yacht making forward progress" at all. I see it as the reverse and IMHO on the occasions it fails and the yacht is driven back there is the potential for disastrous rudder damage.

I must say that my copy of Pardey is on the boat and not with me so I have not been able to check but in support of what I am saying please look at

http://www.morganscloud.com/2009/03/17/stopping-wave-strikes-while-heaved-to/

Of course there are different designs of sea anchors but my submission is that all of them will at some stage allow the boat to move sternwards at speed.

In all of this I accept 'It depends' - it depends on the boat and the circumstances. So far my reading and experience has said for my deep keel if I have the room I should run off. I understand that for Cats. and light displacement the situation is very different.

 

[VO5]

Ceirwan thanks for this. This is not my reading of the situation but I am making this comment to try and get to the heart of this debate so please do come back to me, of course I could be wrong. In this post I am not considering Cats.

I started this thread to try and understand what I saw as discrepancy between tactics advocated by Coles/Bruce and the Pardeys. It seemed to me that the sea anchor off the bow even when modified by a bridle had the great potential disadvantage of the boat being driven back on her rudder. I feel sure that would be the weakness in my own boat and, to date, I have always been able to run off.

I don't see the Pardey approach as "prevent the yacht making forward progress" at all. I see it as the reverse and IMHO on the occasions it fails and the yacht is driven back there is the potential for disastrous rudder damage.

I must say that my copy of Pardey is on the boat and not with me so I have not been able to check but in support of what I am saying please look at

http://www.morganscloud.com/2009/03/17/stopping-wave-strikes-while-heaved-to/

Of course there are different designs of sea anchors but my submission is that all of them will at some stage allow the boat to move sternwards at speed.

In all of this I accept 'It depends' - it depends on the boat and the circumstances. So far my reading and experience has said for my deep keel if I have the room I should run off. I understand that for Cats. and light displacement the situation is very different.

I can see that the lightbulb is beginning to glow in this discussion.

Think about this:~

What happens if you are in open water with sufficient steady wind to whip up horses if the wind remains steady ?

 

[serini]

Horses

I can see that the lightbulb is beginning to glow in this discussion.

Think about this:~

What happens if you are in open water with sufficient steady wind to whip up horses if the wind remains steady ?

A bit obtuse but if it helps the light go on!

Depends 'What happens?' means. Force 5? Not much as far as the boat and where I am going is cocerned. I wasn't posing the sea anchor question for a 5! If you mean 'What happens to the water' then the White horses are a symptom of the breaking crest moving differently from the underlying wave - the wind over the wave is overcoming the co-hesion of the wave - breaking the surface tension - is this what you mean or am I being thick??