33 CFR § 183.35 - Maximum weight capacity: Outboard boats.
(a) The maximum weight capacity marked on a boat that is designed or intended to use one or more outboard motors for propulsion must be a number that does not exceed one-fifth of the difference between its maximum displacement and boat weight.
(b) For the purposes of paragraph (a) of this section:
(1) “Maximum displacement” is the weight of the volume of water displaced by the boat at its maximum level immersion in calm water without water coming aboard except for water coming through one opening in the motor well with its greatest dimension not over 3 inches for outboard motor controls or fuel lines. For the purpose of this paragraph, a boat is level when it is transversely level and when either of the two following conditions are met:
(i) The forward point where the sheer intersects the vertical centerline plane and the aft point where the sheer intersects the upper boundary of the transom (stern) are equidistant above the water surface or are equidistant below the water surface.
(ii) The most forward point of the boat is level with or above the lowest point of water ingress.
(2) “Boat weight” is the combination of:
(i) Hull weight;
(ii) Deck and superstructure weight;
(iii) Weight of permanent appurtenances; and
(iv) Weight of full permanent fuel tanks.