As you have posted this in the liveaboard section i assume you do, or will be livingaboard, if so then hull speed is irrelevant, as i own a cat and can testify that as soon as you put gear on it for cruising it slows down, (the smaller the cat the greater the effect), the only thing i found to be effective was to be pretty brutal when it came to keeping the boat light, even to the extent of fitting smaller water tanks, and fitting plastic fuel tanks, it has worked but it was a lot of effort,.......keith