Manning requirements on certain vessels. Hearings before the Committee on Merchant Marine and Fisheries, House of Representatives, Seventy-seventh Congress, first session, on H.R. 554, a bill to exempt sail vessels from the provisions of section 13 of the Act of March 4, 1915, as amended, requiring the manning of certain merchant vessels by able seamen, and for other purposes; and H.R. 2520, a bill to amend the act entitled "An act to except yachts, tugs, towboats, and unrigged vessels from certain provisions of the Act of June 25, 1936, as amended," approved June 16, 1938.