(e)Internal buoyancy. Buoyant material of suitable unicellular plastic foam shall be installed in the rescue boat. This material shall be protected from mechanical damage. It shall be distributed uniformly in the boat and such that at least one-quarter of the required volume is located at the sides of the boat. The minimum amount of buoyant material, in cubic feet, shall be determined by the following: B = 2 + (W - W ÷ d) ÷ 62.4 - c (1)
Where:
B = Volume of buoyant material required in cubic feet.
W = Weight of equipped boat, in pounds.
d = Specific gravity of hull material.
c = Density of buoyant material, in pounds per cubic foot.