Don't put yourself in a situation where you'll have to deal with them. When you see a squal line, get to shore immediately. This weekend I got caught out in the middle of a horrendous line of storms in a lead-hauler that drafts 7'+ and when we turned into the wind to help a san juan, the wind (54 highest witnessed on knotmeter) had us on our rail with no sails up. I'd have to say that you'd be screwed on any kind of beachcat in that kind of weather. Waterspouts just don't come out of the middle of nowhere *unless you're in Miami*.