33 C.F.R. § 401.39
Before a vessel enters a lock:
(b) The eye of each mooring line shall be passed outward through the fairleads at the side.
(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)
[39 FR 10900, Mar. 22, 1974, as amended at 47 FR 51122, Nov. 12, 1982; 70 FR 12972, Mar. 17, 2005; 76 FR 13089, Mar. 10, 2011]