Dive in the water and swimm to the top of the mast. Turn it with the cat completely leeward. Then push the masttop down under you, stand on it in the water. With a stormy wind drifting you leeward, the cat will push itself turtle.
Ok, well...with a boat on it's side in a ripping wind, there's no way you are swimming out to the end of the mast on purpose. I've been in situations where I was lucky to just be able to stay with the boat...even with a hand hold on trampoline lacing, the boat was moving so fast on it's side I couldn't climb aboard without help. This was in about 30+. There would be no way I could swim out to the end of the mast and certainly no way I could swim the boat into a mast-downwind orientation. Auto-righting was a definite possibility and we were rushing to try and get into a righting position quickly so we would be ready in any case.
