View Single Post
  #5   Report Post  
posted to rec.boats.cruising
Gary
 
Posts: n/a
Default parachutes & drogues

Tamaroak wrote:
My experience with motor boats is that when they lose power they always
face beam to the seas. Larger boats with deep keels take longer to
assume this position, but they all seem to get there quick enough. Some
say the right wave equal to the beam of the boat will flip it over.

The rule of thumb is a breaking wave one third the beam of the boat is
dangerous. (Heavy Weather Sailing)

Neither of my boats would survive that, and I would probably have just
enough time to deploy the EPIRB and go over the side before they sank.

My understanding of the distinction between drogues and sea anchors is
that drogues go over the stern to keep a sailboat from going too fast
down the face of a wave. Sea anchors are deployed from the bow (from
powerboats anyway) to keep the boat facing the waves in the only
position they can handle big water. The boats only move at 1 - 1.5 knots
in this condition. If I deployed either of my sea anchors from their
respective boats' stern in any kind of seas, they would be pooped and
sink. No one that I've read recommends deployment of a sea anchor from
anyplace other than the bow of a powerboat.


I think drogues and sea anchors are different designs of devices for the
same purpose. You can rig either off the bow or stern or one of the
quarters. To me the drogue is less drag than a sea anchor and serves
more to slow the boat while the sea anchor trys to stop the boat. That
is why drogues are more likely rigged from the stern (to slow the boat)
and sea anchors from the bow (to stop the boat or minimize drift). If
you rig a drogue from the bow you risk damaging the rudder with the
continued backward movement of the boat. If you rig a sea anchor from
the stern you risk waves breaking into the cockpit of the stationary boat.

The sea anchor has to be big enough to stop the boat and hold it facing
the waves. This takes a huge parachute. It is hooked to your ground
tackle and you may need 300' of rode. Having some chain in there to
provide a catenary effect is recommended. And you have to continually
watch for chafing. This process involves considerable stress on the
point the rode connects to the boat. One needs to be able to add a
little length (you probably aren't going to be shortening it any) and
have old fire hose, rags or something else where the rode meets the
fairleads, hawsehole, or whatever.

The Jordan series drogue seems to be the hot setup these days.

And if you pay attention to the weather and nothing fails on your boat,
you've wasted the cost of the sea anchor, just like all that money
you've spent on insurance over the years. The only real difference is
that if the **** really hits the fan and you really need this device,
you get to collect instead of your beneficiaries.

Capt. Jeff