Section 401.37 - Mooring at tie-up walls(a) Upon arrival at a lock, a vessel awaiting instructions to advance shall moor at the tie-up wall, close up to the designated limit or approach sign or to the ship preceding it, whichever is specified by the traffic controller or an officer.(b) Crew members being put ashore on landing booms and handling mooring lines on tie-up walls shall wear approved personal flotation devices.39 FR 10900, Mar. 22, 1974, as amended at 47 FR 51122, Nov. 12, 1982; 65 FR 52914, Aug. 31, 2000; 70 FR 12972, Mar. 17, 2005; 73 FR 9954, Feb. 25, 2008; 81 FR 13746, Mar. 15, 2016 68 Stat. 93-96, 33 U.S.C. 981-990 , as amended and secs. 4 , 5 , 6 , 7 , 8 , 12 and 13 of sec. 2 of Pub. L. 95-474 , 92 Stat. 1471