46 C.F.R. § 15.1109 Watches.
Title 46 - Shipping
Each master of a vessel that operates beyond the Boundary Line shall ensure observance of the principles concerning watchkeeping set out in STCW Regulation VIII/2 and section A-VIII/2 of the STCW Code.
Title 46: Shipping
PART 15—MANNING REQUIREMENTS
Subpart J—Vessels Subject to Requirements of STCW
§ 15.1109 Watches.