Tanker construction. : Hearings, Ninety-third Congress, first session on Proposed Regulations Promulgated by the Coast Guard as Required by Title II of the "Ports and Waterways Safety Act of 1972," To Require That All Large Tankers Contracted for After January 1, 1976, Entering U.S. Territorial Waters, Be Equipped with Segregated Ballast Tanks / (U.S. Govt. Print. Off, 1973)