Re: 140hp on 125 rated boat
As for safety, you're obviously playing with fire. As for legality, some states can issue citations for exceeding the HP rating of the hull, but I don't think it is common. However it IS common for insurance companies to deny coverage if you are over-powered.<br /><br />With that disclaimer out of the way, the HP rating of the hull isn't a magic number of the power it can handle. It is based of a mathematical formula, [(Length * Transom Width * 2) -90] where length and width are in feet, usually out to 2 decimal places, and then rounded up to the nearest 5 horse.<br /><br />So an 18 ft boat, with a transom with of 5'6" would have a HP rating of (18*5.5*2)-90=108, or 110HP rounded up.<br /><br />Now, there IS a secondary test, called a high-speed turn test. At full speed, with the max HP outboard properly propped, the boat must be able to survive a sudden 180 degree turn of the wheel without loss of control or ejecting the pilot.<br /><br />If the hull fails the high-speed turn, the manufacturer can either place a warning plate on the dash, or de-rate the hull.<br /><br />Now that you know where the rating comes from, you can make your own decisions.
