Can flip a houseboat! We had one (85' long)go under, upside down then righted itself but still underwater for the most part. I think it was a Catamaran style hull. Another one started to tip over when the hot tub emptied but luckily they were able to beach the bow and tie it off. I heard both boats were trying to turn into the wind but didn't have time. Luckily no one was hurt...