46 CFR § 329.2 - Sec. 2 Voyage numbers.
(a) The voyages of National Shipping Authority vessels shall be numbered consecutively commencing with voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1.
(b) The continuity of NSA voyage numbers shall not change with berth agency operations or in the transfer of vessels to other General Agents.
(c) The General Agents' designated abbreviation and voyage numbers shall terminate upon transfer of the vessel and the succeeding General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1.