46 CFR 160.049-2 - Types and sizes.
(a) Type. Buoyant cushions shall be of the box type, i.e., have top, bottom, and gusset. Pillow type cushions without a gusset are not acceptable.
(b) Sizes. Buoyant cushions shall have not less than 225 square inches of top surface area, shall contain not less than 630 cubic inches of buoyant material, shall not be less than 2 inches thick, and shall have width no less than 12 inches and length no less than 15 inches, respectively.