I looked at the drawings that show the large chain catenary loop in the proposed sea anchor
system. The large loop of chain going into the water
defeats part of the purpose of a parachute sea anchor
. You want the parachute and 500 foot rode to be fairly tight all the time because you are using the parachute to protect you against a wave strike that could capsize
or broach your yacht. If the rope
between the parachute and the yacht is not fairly tight, your boat will be moved backward if you are hit by a breaking sea. That is one of the criticisms of Steve Dashew about using parachutes. He feels that your boat will get knocked backwards and you also may get rudder
damage when you move backwards if you are hit by a big wave. If you put a big loop of chain in your parachute sea anchor
set up, then you will be at risk for exactly what Dashew is saying.
When we were caught in a winter storm 300 miles north of New Zealand
, we put out our parachute sea anchor
on 500 feet of double braid nylon and an eighty foot bridle
. In the forty five to fifty knot
winds, the sea anchor rode remained under load all the time, and our catamaran
bobbed up and down in the waves without getting knocked backward. We drifted about half a mile in 17 hours while attached to the parachute.
When I am in a storm, I don't want catenary in my parachute sea anchor rode. I want a tight rode that will protect me when I am hit on the bows by breaking seas, and I want that protection to start immediately rather than after I have been knocked backwards a distance 20 or more feet.
I have sea anchor chainplates installed in the decks on my bows, and I am not afraid to keep my sea anchor under constant strain. I also would think that a sea anchor under constant strain would be more stable - the parachute would be fully inflated in a configuration ready to protect you if you had a massive wave strike.
The author of the article also mentions the jerking effects of an all nylon rode. We never experienced any jerking motion from our sea anchor. The ride on the parachute was as smooth as silk.
Anyway, the parachute worked as advertised for us. I wouldn't go offshore