46 U.S.C. § 11103: Slop chests

(a) A vessel to which section 11102 of this title applies shall be provided with a slop chest containing sufficient clothing for the intended voyage for each seaman, including—(1) boots or shoes; (2) hats or caps; (3) underclothing; (4) outer clothing; (5) foul weather clothing; (6) everything necessary for the wear of a seaman; and (7) a complete supply of tobacco and blankets. (b) Merchandise in the slop chest shall be sold to a seaman desiring it, for the use of the seaman, at a profit of not more than 10 percent of the reasonable wholesale value of the merchandise at the port at which the voyage began. (c) This section does not apply to a vessel on a voyage to Canada, Bermuda, the West Indies, Mexico, or Central America, or a fishing or whaling vessel.