How to deploy a sea anchor

Lucky Day · Posted: Thu Nov 22, 2007 12:53 pm Post subject: How to deploy a sea anchor

First - Happy Thanksgiving to everybody who participates and lurks here. This is a great community!

I split this question off from the open ocean suitability thread currently going. How would one deploy a sea anchor from a CD25? Would there be more than one way to deploy it, and if so, what would be the background to that.

Alyssa Jean · Posted: Thu Nov 22, 2007 1:47 pm Post subject:

A parachute sea anchor is basically a drag device. Normally deployed off the bow to windward, it is designed to hold the bow into the wind and waves. This stabilizes the motion of the boat while maintaining a safe attitude to the seas. Forward motion is stopped, but some leeward drift ideally, no more than 1 or 2 knots—occurs. The usual rode length is 10X LOA and should be nylon which can stretch for shock relief. You should also try and distance the sea anchor to be in phase with the waves.

A trip line is usually used also to dump the anchor and retrieve it.

Lucky Day · Posted: Thu Nov 22, 2007 1:59 pm Post subject:

Does it completely overcome the 25's tendency to hunt faced to the wind with no way on?

SEA3PO · Posted: Thu Nov 22, 2007 2:49 pm Post subject:

My son gave me one as a gift.....he gives me all sorts of safety equipment... I wonder what he is trying to tell me.....
Anyhow... What does it attach to ?? I would think the Bow eyelet where the trailer cable attaches would be best.... but in a storm I sure am not going up there...

It didn't come with instructions.....

Joel
SEA3PO

GxK · Posted: Thu Nov 22, 2007 2:59 pm Post subject: How to deploy a sea anchor

When experienced C-Brats provide advice and suggestions in this thread, I'd request they address two points of interest.

Is the advice the same for a TomCat as a monohulled C-Dory? Are the standard cleats on the boats from the factory strong enough to handle the load of a sea anchor?

And a third question, if you please: Are drogues pertinent to the boats represented in this forum?

--Georgs

SEA3PO · Posted: Thu Nov 22, 2007 5:04 pm Post subject:

Might you use a snap shackle to attach it ???

I would guess that you would want floating line ??? probably 3/8"

Or.....could I connect it to my anchor line ???just unshackle the anchor and chain....and connect the sea anchor...

Joel
SEA3PO

Captains Cat · Posted: Thu Nov 22, 2007 5:27 pm Post subject:

thataway · Posted: Thu Nov 22, 2007 7:28 pm Post subject:

The sea anchor is deployed off the bow, to attempt to keep the bow into the wind as the boat drifts slowly backward or to leeward. For the most part, boats like the C Dory will not lie directly into the wind--either from an anchor or sea anchor. The bow eye would be ideal, for a sea anchor, because if you use a screw type of D shackle, into a spliced eye with a thimble there will be no chafe from the deck or fittings on the deck. The problem with the bow eye, is reaching it safely when the boat is disabled and drifting. It is a bit easier to reach the bow eye on the Tom Cat, than a CD 22 or CD 25. A snap shackle is generally not strong enough, and it presents the possibility of comming open. The bow eye could be used, if re-enforced, and backed properly. The line would have to be attatched ahead of time--or some risk taken to secure it.

You want the sea anchor to float, but just below the surface. Many will use a short length of chain attatched to the sea anchor with a swivel, with a float at the place where the rope rode and chain meet. Chafe is a major problem--some larger boats will have a length of chain shackled to the nylon rode at the bow end, and then that shackled to a strong point or a cleat. I prefer to handle chafe on anchor or other lines foreward with small diameter fire hose. (my local fire chief gave me a lifetime supply) I would say that generally the bow cleat is strong enough for a Sea Anchor--but I would be sure that there are either fender washers or a plate of metal under the bolts securing the bow anchor. (I prefer an aluminum plate). I have mixed feelings about the trip line on a C Dory. Definately this is necessary on larger boats, but there is always a risk of the trip line wraping around the sea anchor and the rode--this causing a fouling and then loss of effectiveness--and even compounding where it became wrapped in the running gear, since there was no longer much resistance foreward, and the boat's bow blows off. With a boat as light as the C Dory, one could drive and pull the boat up to the sea anchor and horse it a board. (difficult to do as the boat and sea anchor gets bigger).

The actual deployment on a C Dory or Tom Cat, would probably be best accomplished via the foreward hatch--I would not go foreward on the side deck in heavy sea conditions. Now, sometimes in the Gulf of Mexico, fishing boats lie to sea anchors at night and in this calm water application, it would be safe to walk around (usual precautions with life jackets, safety harnesses and lifelines).

The Jordan Series drogue is to be used from the stern, mostly to slow a boat down as in running a breaking inlet and prevent pitch poling. I would not consider a series drogue on a C Dory in heavy weather. There may be use for it in fishing, to slow the drift of the boat--but the sea anchor will also do that. The stern of the C Dory is the most vulnerable part and you don't want to expose this to the waves.

The best book on Sea Anchors and Drogues is by Earl Heinz.

Bear in mind that an appropiate Para anchor will cost about $350 for a 22 footer and $600 for a CD 25 or the Tom Cat. I don't own one and don't see that I would be going anyplace where I would use one. But if I was going offshore in some areas, I would give it serious consideration. We have always managed to keep way on even in very rough weather. The control with way one, even in hurricane force winds allowed us to maneuver appropiately and run off with the wind and seas. Near a coast, or in a small craft, one may not have these options. But I know of a multihull which broke up when riding to a sea anchor, so the sea anchor is not the ultimate solution.

CW · Posted: Thu Nov 22, 2007 10:52 pm Post subject:

People use sea anchors all the time on the Columbia. When anchored with the rake type anchor with a long rode, we fish off the stern pulling plugs or spinners for salmon & steelhead or bait for sturgeon, often in a line right next to other boats. We run one or two sea anchors off of the stern cleats or rope tow eys behind the boat. This keeps the boat from being pushed side to side by the wind (and into other boats) and generally helps it track straighter. Many guys don't bother to tie on the second lighter line to the grommet at the smaller funnel end. They don't know that this line is what you pull them in with, effectively "dumping" the water and enabling you to pull it in quickly with just one hand, minimal drag. They really have a tussle to pull it in full of water when they are fighting a fish. By changing the position (starboard, center or port) of where it is tied, you can shift the lie of your boat several feet too. They are classified by diameter (e.g. 16", 24", 36") , made of heavy nylon and cheap, $15 - $30. I tie about 7 ft. of 3/8" rope to it, small braided 1/8th to the funnel. Some guys run a float down the rope, I don't as it increases the likelihood of it running afoul the prop. C.W.

thataway · Posted: Fri Nov 23, 2007 11:05 pm Post subject:

The drogues used for fishing are considerably smaller than a sea anchor. The recommended sea anchor size for a 22' C Dory is 9 foot diameter, and for the 25 or TC 255 is a 12 foot diameter unit.

We carried 24 to 36" drogues with our man overboard gear to decrease its drift if it had to be deployed on ocean voages.