I owned a 18' hewes sea runner it had a 90 horse Yamaha on it and was enough power but I would say a 75 would be a little under powered at times. if you were to put 3 or 4 guys in it and all your gear it would be working hard. i have a 18' northriver now with a 90 and it's a bit under powered with a few guys and crab pots or shrimp pots, but it is a much heavier boat