46 CFR § 42.07-15
Zones and seasonal areas
April 15, 2021
(a) A vessel subject to 46 U.S.C. 5101-5116 or the 1966 Convention shall comply, as applicable, with the requirements regarding the zones and seasonal areas described in subpart 42.30.
(b) A port located on the boundary line between two zones or areas shall be regarded as within the zone or seasonal area from or into which the vessel arrives or departs.
[CGFR 68-60, 33 FR 10053, July 12, 1968, as amended by USCG-1998-4442, 63 FR 52190, Sept. 30, 1998]