DIY Sea Anchor or Drogue

[clivehall]

Ive got several "Builder Bags" from recent building works at home, & I'm wondering about using them as a sea anchor?

They hold a cubic yard of sand etc, & are rated with a safe working load of 1000 KG with a safety factor of 5 to 1, so theyre pretty strong, & made from non rotting plastic woven material.

I'm thinking of putting one on the boat (36 ft Westerly) for use from the stern as a drogue if I.m running in very bad weather.

I'm also wondering about using several together as a sea anchor. A parachute anchor for my boat would be 12 to 15 ft diameter & would cost maybe £500 plus? Meanwhile I've got all these bags sitting in my garage....

I thought I could put 9 together in 3 rows of 3, with 16 shroud lines, to give a 9ft square anchor.

I sincerely expect never to have to use it but I now use my boat in the Med where weather forecasts are not as easy to get ( Navtex doesnt work very well in northern Majorca) & it seems storms can be sudden & vicious.

Someone must have thought of this idea before - anyone got any comments or experiences with this?

 

[Roberto]

You may find a few interesting suggestions here:

http://www.sailrite.com/droguereport.htm

although the connections between your bags and the rode should be somewhat stronger..

 

[tony_brighton]

I'd have thought one would be enough as a drogue to slow you down - providing its weighted.

 

[summerwind]

I think you have the makings of an excellent idea. One question though, how would you ensure that the mouth of the bag(s) stayed open?

Regards

 

[ParaHandy]

Have a look at Adlard Coles Heavy Weather book (I think that is the title). A Brit was asked what drag device he used, to which he replied "1 tonne sack". So it has been done but as a drogue.

I have a similar size of boat and came to the conclusion (from previous posting on YM board) that the deck fittings might not be strong enough to hold a sea anchor. The forces required to stop a boat, head to wind, in gale force plus are greater than one might think. If she slips backwards, the rudder's gone.

 

[Twister_Ken]

Trust you've got plenty of storage space aboard!

 

[romany123]

Just out of intrest, what westerly do you have? I sail a Conway.
Dave

Dave

 

[Roberto]

Yes one should be enough. The uscg drogue should be deployed from the stern, and it should be used to slow down the motion of the boat rather than stop it; the many cones it is made of should ensure fewer shocks to the boat and that the rode is always under tension.
The sea anchor instead should almost stop the boat from the bow.

Which is better is of course open to endless discussions, and having never tried any of the two I am in the peaceful field of perfect ignorance. Anyway, I find the uscg drogue more intellectually appealing, in the comfort of my chair

 

[Guest]

A bucket would do the job if you had no alternative pop a few large holes in it .Even for that matter a length of rope with something tied to it would give some help .
I looked at one of those fancy chutes at the LBS !! big bit of kit .
What about using a small car tyre as an inline shock absorber ,they are used when towing boats and certainly help reduce sharp pull's.
YBW did a good copy about sea anchor's and drogues some years back which was very good stuff.

 

[Guest]

Nice idea but ...........

Sorry Clive but I had to grass you up as the EU policy is as follows :-

Our 'end of life' policy for builders bags has to conform with policy no zx34r662 where they have to be neutralized to inert status, and be co mingled with stabalized hydro carbon monotone untainted atomised electrons.

Sorry son !

When it comes to employing things like drouges and the like in breaking seas most of us just want to bugger off out of it !

May I suggest two ideas that you may like to work on that could sell well :-

Half sized hot air balloon that self inflates and runs on diesel.

Budget priced mini Lynx helicopter that will automatically fly itself using an Autohelm 2000


Will they be ready for next year's Boatshow ?

 

[gus]

If you fork out £500 for a sea anchor you want your head looked. For a 5th of that price you can get one at http://www.swedeandsons.com/para/index.html

 

[coliholic]

Re: Nice idea but ...........

Ah but the Lynx is no good for you raggie lot is it. Two engines see. And two props (one horiz and one vertical). You'll all be totally flummoxed.

Nope. Think again

 

[Guest]

Some of these are made of polypropaline which has the chafe resistance of warm wax!

Roly, Voya Con Dios, Glasson, Lancaster

 

[clivehall]

Many thanks for the pointer to the drogue report - Havent finished it yet!

 

[clivehall]

Thanks for all the replies - some very helpful tips & I had a good laugh at work today about the Lynx - maybe it would be too much for this poor yottie.

Maybe I better think again??

 

[clivehall]

Yes, mines a Conway, too - centre cockpit ketch version.