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 without it.