I am trying to just gauge if these figues sound about right or to high etc. I have a rinker 270 which including swim platform is 30ft. It weighs about 3.5 ton plus 2 adults fuel tanks full (375 ltrs) i have a yanamar 4lha stzp 230hp diesel. The out drive is a bravo 2 i have no idea about what prop i have on. I am having to do about 3000 revs to do between 19-21knts i also use a lot of trim taps down which does get on the plane quicker as soon as i bring them up the speed drops is this normal? To counter this i would have to increase revs. Do others use trim taps in this way as well as to counter any list? Does use of taps in this way effect fuel consumption? The manual says burn at 3000 revs should be about 40 ltrs an hour i have yet to check this as i will do on my next fill up.