33 C.F.R. § 183.201

(a) This subpart applies to monohull outboard boats that are:

(1) Less than 20 feet in length; and

(2) Rated for outboard engines of more than 2 horsepower.

(b) This subpart does not apply to sailboats, canoes, kayaks, inflatable boats, submersibles, surface effect vessels, amphibious vessels, and raceboats.