46 C.F.R. § 45.51 Types of ships.
Title 46 - Shipping
(a) For the purpose of this subpart, a type A vessel has— (1) No cargo ports or similar sideshell openings below the freeboard deck; (2) Only small freeboard deck openings fitted with watertight gasketed hatch covers of steel; (3) No dimension of a freeboard deck cargo opening greater than 6 feet and the total area not exceeding 18 ft2 ; and (4) No more than two freeboard deck cargo openings to a single cargo space. (b) For the purposes of this subpart a type B vessel is a vessel that does not meet the requirements in paragraph (a) of this section.
Title 46: Shipping
PART 45—GREAT LAKES LOAD LINES
Subpart C—Freeboards
§ 45.51 Types of ships.