33 CFR 183.41 - Persons capacity: Outboard boats.
(a) The persons capacity in pounds marked on a boat that is designed to use one or more outboard motors for propulsion must not exceed the lesser of:
(2) For boats with a maximum persons capacity less than 550 pounds, the maximum persons capacity determined in the following manner:
(ii) Add, in normal operating positions, the dry motor and control weight, battery weight, and full portable fuel tank weight, if any, required by § 183.75 for the maximum horsepower capacity marked on the boat. Permanently installed fuel tanks shall be full of fuel.
(iii) Gradually add weights along one outboard extremity of each passenger carrying area, at the height of the seat nearest the center of that area, but no higher than the height of the gunwale, and distributed equally forward and aft of that center in a plane parallel to the floorboards until the boat assumes the maximum list or trim, or both without water coming aboard.
(iv) Compute the persons capacity in pounds using the following formula: Persons capacity = A/0.6 where A is the total of the weights added in paragraph (a)(2)(iii) of this section.
(b) The maximum persons capacity in whole numbers of persons marked on a boat designed or intended to use one or more outboard motors for propulsion must not exceed the value obtained by adding 32 pounds to the lesser of the values determined in paragraph (a)(1) or (a)(2)(iv), dividing the sum by 141, and rounding off the result to the nearest whole number. If the fraction is less than one-half, round down to the next lower whole integer and if the fraction is equal to or greater than one-half, round up to the next higher whole integer.