Determining horsepower limits on recreational boats

The Coast Guard regulates maximum allowable horsepower on recreational outboard boats up to 20 feet in length. Improved methods of determining the proper amount of horsepower have been proposed, including a new "dry land" formula based on lateral acceleration. A test program was conducted which evaluated the power-related performance of 25 outboard boats of various designs. From this information it was determined that lateral acceleration was not sufficient to set horsepower levels and that a fairly complex formula would be needed to adequately assess the powering-related behavior of the wide variety of hull designs currently available to the consumer.