Section R. 281.517 - Horsepower capacityRule 7. The horsepower capacity of an outboard watercraft, excepting canoes or pontoon craft, shall be determined by either of the following methods:
(a) The horsepower capacity of an outboard watercraft, other than a canoe, and except one dependent solely upon the buoyancy of pontoons or similar flotation devices, shall not exceed the value given by the boat horsepower table in figure 1. The horsepower capacity of an outboard watercraft, other than a canoe, and dependent solely upon the buoyancy of pontoons or similar flotation devices shall not exceed the value given by multiplying the cubic feet of flotation in the pontoons by the pontoon length in feet and dividing by the pontoon diameter in inches. If the pontoons are not circular in cross section, the diameter of the largest circle that can be inscribed in the pontoon shall be used.(b) By reference to a manufacturer's capacity plate installed in a watercraft, if manufactured or offered for original sale in this state on or after January 1, 1968, or in accordance with standards approved by the state waterways commission, or the horsepower capacity recommended by the livery operator, whichever is the lesser. Figure 1 Boat Horsepower Table
Multiply overall length _____ x stern widtth ____ = Factor (both measurements in decimal feet) (nearest whole number)
Remote steering No remote steering and 20' or or transom less than equivalent 20" or equivalent
Factor is: under over over 40 40-45 46-49 50-53 54-57 57 57
B.P. Cap is: 5 10 15 20 25 (2 X Factor) -- 90 (3/4 Factor) -- 20 H.P. Cap = _________ (raise to even 5 h.p. increment)
Mich. Admin. Code R. 281.517