Parachute sea anchor

[KellysEye]

>.....a monohull would have righted itself after flipping over....
Another urban myth!

Err, apart from some extreme racing machines monohulls usually right themselves if all the hatches are closed. I don't see why you think it's an urban myth.

I don't know why the Pardeys would tie a line from the parachute rope to the stern, all monos lie off the wind when riding to a para anchor. Mind you these are the people who go on about cruising without an engine whilst regularly asking to be towed in/out of anchorages.

 

[doris]

Interesting thread but I haven't seen any remarks about recovery.

I have never used a sea anchor in anger but a while ago we went out into Christchurch Bay in some thing like a F6 to play with one. We were in a Bav 350, IIRC, and it all worked fine but the recovery was another matter.

Getting it back on board was tricky. The tripping line only half worked and had we been in real survival conditions I suspect that we would have had to cut it away. I would certainly look at a sea anchor as a probable 'use once' option.

 

[VO5]

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??

No. And you are not thick. I can see you are working at it and hovering on the edge of having an important realisation.

The question is this...If the wind strength is steady the sea is going to build up, not down. It is also likely to develop a swell. The sea will calm if the wind drops.

If the wind drops all is well, but if it doesn't, that is another story altogether.

It is preparing for a worsening condition that engages my thinking, and not the optimistic opposite.

Think of it as a similar decision that has to be made whether to reef or not to reef, and if so, how soon.

 

[VO5]

Interesting thread but I haven't seen any remarks about recovery.

I have never used a sea anchor in anger but a while ago we went out into Christchurch Bay in some thing like a F6 to play with one. We were in a Bav 350, IIRC, and it all worked fine but the recovery was another matter.

Getting it back on board was tricky. The tripping line only half worked and had we been in real survival conditions I suspect that we would have had to cut it away. I would certainly look at a sea anchor as a probable 'use once' option.

Very good point you raise there. I will come back to you on this later.

 

[VO5]

>.....a monohull would have righted itself after flipping over....
Another urban myth!

Err, apart from some extreme racing machines monohulls usually right themselves if all the hatches are closed. I don't see why you think it's an urban myth.
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I don't know why the Pardeys would tie a line from the parachute rope to the stern, all monos lie off the wind when riding to a para anchor. Mind you these are the people who go on about cruising without an engine whilst regularly asking to be towed in/out of anchorages.

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I agree with you. But this is because there is a lot of well meaning advice around but equally a lot of confusion about this very topic.

 

[Ceirwan]

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

Well I didn't read this so I don't know how accurate it is, but I've been on board a yacht (a keel mono hull) that was knocked down to the point of masthead touching the water. I'm pretty sure a multi-hull wouldn't have sprung up from that position like this yacht did.

And the boat may be stable upside down for a few seconds, but the next wave should come along and roll her back again. I'm not talking a racing yacht with a deck wider than an aircraft carrier, I'm talking about the sort of cruising boats I think we're talking about.

A multi-hull I would suggest is more stable upside down with the weight of a mast acting as a Keel and if sails are set working as a brake underwater to damp any rolling motion.

 

[VO5]

Part One.

I think there exists a lot of confusion on this topic because, like many simple ideas, it is not properly explained.
Many people tend to muddle parachutes with drogues.
They each fulfil a different role, although I myself no longer use parachutes (sea anchors) and presently I will explain why.
Imagine in the open sea there is a steel column rising out of the surface, built of such strength that even hurricanes can not knock it down, for instance.
Suppose you substitute this for a sea anchor and you moor to it bow first on a long warp. Now suppose the wind gets up and the seas begin to build...What would happen ?
What would happen is that the boat would face the seas bow on. At first, with wavelets and small waves, the boat would ride them.
But as the intensity of wave oscillation increased, so progressively the moored boat would not be able to cope. Seas would begin to break over the bow. Then later the bow itself would be submerged as bigger waves hit it.
Finally, the bouyancy of the vessel would be overcome by wave action and sheer weight of water, and the vessel would sink.
Even bracing it at an angle to the oncoming seas would not prevent disaster.
Of course this would not happen with flat seas or relatively flat seas or wavelets.
What I am saying is that proportionately with an increase of wind (and a correspondentl increase in wave height and periodicity) so a boat tethered in this way would increasingly risk being sunk.
But a fixed steel pole in open water is not a sea anchor. The difference is that the pole is fixed whereas the sea anchor is not.
But this does not exonerate the vessel from the effect of oncoming seas.
There are many videos to look at of big ships ploughing head on into heavy seas, throwing up spray and digging their bows in. This happens to them because they are on a schedule during a voyage and are rigidly headed in a predetermined direction.

 

[VO5]

Part 2.

My view is that heaving to streaming a parachute from the bow has limited application. The reason for this is that it is effective in calm seas and up to breezes or strong breezes but no higher.
The vessel so tethered would actually be drifting backwards.
At very slow speeds in calm water this is neither here nor there, so to speak.
But the problem arises when the sea and wind build up.
Then the bow is to the sea and the vessel is falling back on the rudder.
Even if the rudder is fastened to remain midships it is not guaranteed that the vessel will drift backwards in a straight line. It places the rudder at risk.
At some stage in the proceedings there may be no other option but to yield to the sea instead of fighting it. At that point recovery of the parachute has to be considered to be able to turn and run. Life already is complicated enough without seeking further aggravation. Sod's law it is that things will geet worse, not better.

 

[VO5]

Part 3

Why would one create extra work and worry for oneself ? What for ? Because the text books say so ? No.
I long ago gave up using sea anchors for the reasons I have explained so far.
If I want to heave to...
in Force 0 -3 I heave to under full Genoa and Full Mainsail.
in Force 4 - 5 I heave to with one reef in the Mainsail and Genoa 1/4 in.
In Force 6 - 7 I heave to with two reefs in the Mainsail and the Genoa 1/2 in.
In Force 7 - 8 I heave to with three reefs in the Mainsail and the Genoa 3/4 in.
In Force 8 -9 I heave to with a handkerchief headsail and a drogue.
in Force 9 - 10 I heave to with a tiny headsail and a drogue.
I have not experienced Force11 in a Yacht.
The drogue is not an ordinary drogue, by the way.

 

[VO5]

Part 4.

An ordinary drogue is cone shaped. It has an opening at the end.
A parachute (Sea Anchor) has a similar design.
Both of them fill with water, and when a tow is exerted on them they remain swollen but do not adjust.
Therefore regardless of the amount of pull exerted, their performance does not vary. Additionally, they have a tendency to spin. This is a frightful nuisance, particularly if a trip line is fitted, as the trip line invariably winds itself around the tow rope and renders it difficult if not impossible to recover. There is no way it can be unwound while the tow rope is in tension. As the cone does not adjust the tension remains constant, without let up.In desperation, sailors have been known to cut them free and lose them in preference to a long protracted and arduous recovery..

 

[VO5]

Part 5.

As I mentioned at the beginning, there is a lot of confusion with regard to Sea Anchors in the form of Parachutes. This is because the idea is rooted in popular sailing culture. Nearly every author repeats the same missive. One copies the other one and the next copies the next.
The truth is, that parachute anchors are old hat.
The idea of towing them as if they were a drogue is equally unsatisfactory, not only because they have a tendency to spin, but more importantly because they don't do the job properly.

 

[VO5]

Part 6.

We have seen how heaving to can be done without the use of a sea anchor. In fact, in some cases it can be a distinct disadvantage to stream them if there is the slightest risk of conditions worsening.
What is needed is proper progress, instead of clinging to clumsy outmoded ideas and practices.
I have a drogue which is in two sections, like a smaller bottomless bucket behind a larger bottomless bucket.
This drogue does not spin at all.
It can be used as a sea anchor or a drogue, but its advantages are remarkable.
Because it is in two parts, it responds to the pull exerrted on it.
Therefore it pulls at the right time and does not at the wrong time.
Its effect is that the pull is self adjusting.

 

[VO5]

Part 7

As its pull is self adjusting it does not matter which end of the vessel it is streamed from, in principle.
But because the heaving to under (say a parachute) can be interrupted by a decision to run, then conveniently it can by choice be streamed from astern.
Rigged with a Y brace, it will keep the stern to the sea.
As it is self adjusting, it will exert a greater pull when the vessel is surfing from the crest of a wave into the trough.
When the vessel arrives in the trough, it self adjusts again.
The vessel then settles into a rhythm, with a tendency to settle in the troughs. This makes the experience incomparbly more comfortable than fighting the sea all the time.
When running, it makes the action smoother.
When streamed in a hove to situation it performs like a parachute.
But perhaps the most favourable feature in its favour apart from the priorities
of keeping the stern square to the sea to prevent broaching and its feature of settling the vessel in the troughs, is the amazing ease of recovery.

 

[VO5]

Part 8

Recovery is very easy as once the Y brace has been negotiated by one of the sheet winches, the tow rope (which is 3 1/2 boat lengths ) is easily winched in on a self tailer. At the end of the tow rope is fitted a thimble, followed by a shackle, followed by 10 ft of chain, followed by another shackle that secures the drogue.
After having been introduced to this by a friend, I will never revert to using either a Jordans or a Parachute sea anchor, ever.

 

[Phoenix of Hamble]

An interesting series of posts VO5

Could you explain what you mean by 'heave to' with a small headsail and a drogue?

(as clearly you don't mean the classic hove to of main balanced out by backed foresail causing the boat to forereach)

Do you mean drogue off the bow and the headsail just blowing the head off a fraction?

Or do you mean more like the blog posted much earlier in this thread of the drogue streamed astern but from forward of the beam?

Or do you mean with the drogue streamed astern?

 

[Phoenix of Hamble]

and one further question regarding your suggested tactic...

If you do mean deploying the drogue from the bow streamed forward, what would be your strategy for attachment to the boat?

My concern would be that with some foresail still up, then should the line be through the stemhead then there is a serious risk of side load on it causing damage in the very place you wouldn't want it under those conditions... which would leave a bridle as an option, but then to use fairleads (not sensible i'd imagine) or just over the toe rails, which would need some significant attention paying to chafe

 

[VO5]

An interesting series of posts VO5

Could you explain what you mean by 'heave to' with a small headsail and a drogue?

(as clearly you don't mean the classic hove to of main balanced out by backed foresail causing the boat to forereach)

Do you mean drogue off the bow and the headsail just blowing the head off a fraction?

Or do you mean more like the blog posted much earlier in this thread of the drogue streamed astern but from forward of the beam?

Or do you mean with the drogue streamed astern?

Small handkerchief headsail sheeted tight midships, Seabrake towed from the stern cleats using a Y brace.
I will post more detail tomorrow. I keep on getting cut off here, very frustrating.

 

[VO5]

and one further question regarding your suggested tactic...

If you do mean deploying the drogue from the bow streamed forward, what would be your strategy for attachment to the boat?

My concern would be that with some foresail still up, then should the line be through the stemhead then there is a serious risk of side load on it causing damage in the very place you wouldn't want it under those conditions... which would leave a bridle as an option, but then to use fairleads (not sensible i'd imagine) or just over the toe rails, which would need some significant attention paying to chafe

Having any drogue over the bow in anything but a calm sea is asking for trouble with a capital T as I explained in my previous posts, for the various reasons I present.

This is without considering the problem of chafe.

I have heard of several cases in which the rope parted at the bow roller, leaving the vessel in a very vulnerable situation.

I have bow cleats and fairleads forward but even so I would never do it, as I do not consider it to be prudent seamanship again for the reasons I presented in my previous posts.

I always stream from astern, from the cleats on the quarters, using a specially constructed brute of a Y brace with small eyes, just big enough to slip over the cleats and wormed, parcelled, covered with burlap, stitched, etc., with 10 tucks on each splice just to make sure..

The foresail, the size depending on how much wind there is, very firmly sheeted exactly midships using both Genoa sheets.

 

[VO5]

I forgot to mention..
And the wheel firmly lashed, and the rudder secured midships.
All other canvas off. The sprayhood down and secured. Storm boards in. Ventilators to face forward, or if convenient, capped. Double the sail ties on the mainsail. And the boom, double secured too.

 

[Boo2]

VO5 : A large part of what you have most tediously spouted is simple garbage. I am going to deal only with one part of it :

its advantages are remarkable.

I have never been to sea in anything worse than F6 but a key disadvantage of single point drogues and sea parachutes has been very widely reported by those who have used them in storms. This is that they will inevitably be thrown forward by a large breaking wave with consequent loss of control of the yacht and the attendant risk of being rolled.

This defect has been reported by people trailing chain, anchors and assorted other weights in attempts to keep them below the surface but to no avail. Basically if the wave is as tall as your mast then it is big enough to throw any weight forward.

This point has been made to you before and you just ignored it. I suppose you will ignore it this time too, but no single point drogue can avoid this problem no matter how many buckets it's most cleverly made from.

Adlard Coles' book give several examples of boats surviving quite comfortably using distributed drogues (including simple trailing warps or lines) from the stern. These should suffer to a much lesser extent from wave action as there should always be a substantial component of drag from parts of the drogue in other parts of the wave systems at any one time.

When I get a boat my intention is to carry a JSD with the intention of streaming it from the stern, and from the reading I've done this is the best proven of all the alternatives. I should say though that Plan A is to have gone down the pub instead of putting out to sea...

Boo2