So far I have not had to use either a Sea Anchor or series Drogues, fortunately. I am aware of at least one cat which parished when riding to a sea anchor in a very bad storm. I agree with Dennis, I would rather keep moving if at all possiable. One of the other features of a series drogue is to prevent pitch polling, when the height of the waves begin to equal the waterline. I was once in a situation where it was very close to this. I surfed the boat down the quartering waves--not directly down wave. I had a about 20% of the "usual" sail area in a storm staysail foreward, which kept the center of effort forward of the center of lateral resistance, and the engine ticking over to be sure that I always had a flow of water over the rudder, even in the turbulance of the waves. I feel that this is a trick well worth remembering, because if the rudder stalls, you risk loosing control and broaching or taking a path which may not be the best for the vessel's survival. This was in a monhull, but I feel that the principle remains the same. Control is important. Bob Austin