The minimum weight of T-55 turbine-powered boat is 6575 pounds. For T-53-powered boat it is 3800 pounds and for a piston-powered boat it is 5775 pounds. Many new boats will weigh under these minimums and will add ballast to come up to the minimum weight, added in areas that help handling. As a boat ages and requires structural repairs, they will usually gain weight due to the material added in the repairs