I must say that this is an interesting and thought-provoking discussion. I have all the gear but have never deployed it anger (I suspect getting the parchute back might be a pretty big task since even when conditions moderate it may still be blowing 30 knots.
Couple of notes:
- I think the size of the parachute matters. You don't want to be stopped, you do want to slide sideways. We have an 18' chute for a 36,000 lb boat. This was bought by the first owner and is the recommended size for the boat. Too big and it might act as too much of a brake and increase the loads on everything.
- Jon, my sense is that being anchored and using a midship bridle is not the same, dynamically, as doing it with a parachute since the entire system - boat and sea anchor rig is free too move sideways rather than being tied to a point in space. Also, according to the pictures and diagrams in the Pardey's boat there is a considerable amount of force on the bridle so the angle in the main line is significant, reducing the ability of the snatch block to slide forward and back too much. I get the impression that the purpose of the snatch block is mainly to reduce the potential for chafe.
In South Africa doing lots of boat stuff. Departure north from Cape Town around December 15th. Arrival in the Caribbean around the beginning of February, after 5300 miles or so.