im not really sure about the speed, but i would definatley say that the advertised 40+mph is lagit. My boat flys, but i just hate having to play with the trim tabs. with the tabs down, in rough conditions, the boat is super stable. but with the tabs up, its all over the place. and i hate having to bring it in and try to fine tune it every time i drive it. i guess you just have to find an overall good all around setting, for them.