(a) The OCMI determines the minimum number of mates required for the safe operation of inspected vessels.(b) The minimum number of mariners holding a license or MMC officer endorsement as mate required to be carried on every inspected, self-propelled, seagoing and Great Lakes vessel, and every inspected, seagoing, passenger vessel must not be less than the following, except when reductions are authorized under paragraph (e) of this section: (1) Vessels of 1,000 GRT or more (except MODUs)-three mates (except when on a voyage of less than 400 miles from port of departure to port of final destination-two mates).(2) MODUs of 1,000 GRT or more: (i) Three mates when on a voyage of more than 72 hours.(ii) Two mates when on a voyage of more than 16 but not more than 72 hours.(iii) One mate when on a voyage of not more than 16 hours.(3) Vessels of 100 GRT or more but less than 1,000 GRT-two mates (except vessels of at least 100 but less than 200 GRT on voyages which do not exceed 24 hours in duration-one mate).(4) All vessels of less than 100 GRT-one mate (except vessels on voyages not exceeding 12 hours in duration may, if the OCMI determines it to be safe, be operated without mates).(5) An offshore supply vessel of 100 GRT (100 GT ITC if GRT is not assigned) or more, but less than 6,000 GT ITC (500 GRT if GT ITC is not assigned) as defined in § 125.160 of this chapter-one credentialed mate (except when on a voyage of at least 600 miles-two credentialed mates). A voyage includes the accrued distance from port of departure to port of arrival and does not include stops at offshore points.(6) An offshore supply vessel of at least 6,000 GT ITC (500 GRT if GT ITC is not assigned) as defined in § 125.160 of this chapter-two credentialed mates provided that the OSV meets the requirements in 46 CFR 15.1111 (except when on a voyage of more than 600 miles-three credentialed mates). A voyage includes the accrued distance from the vessel's port of departure to the vessel's port of arrival. Stops at offshore points or facilities do not constitute separate voyages; stops at offshore points or facilities are included in the total accrued distance between the vessel's port of departure and the vessel's port of arrival.(c) An individual in charge of the navigation or maneuvering of a self-propelled, uninspected, documented, seagoing vessel of 200 GRT or over must hold an appropriate license or MMC authorizing service as mate.(d) Each person in charge of the navigation or maneuvering of a towing vessel of at least 8 meters (26 feet) in length must satisfy the requirements of § 15.805(a)(5) of this part or hold a license or MMC authorizing service as either- (1) Mate (pilot) of towing vessels; or(2) Mate of inspected self-propelled vessels greater than 200 GRT within any other restrictions on the officer's license or MMC, holding either- (i) A completed TOAR bearing the signature from a Designated Examiner and stating that the Examiner found the candidate proficient; or(ii) A license or MMC with officer endorsement for towing vessels.(e) The OCMI may increase the minimum number of mates indicated in paragraph (b) of this section where he or she determines that the vessel's characteristics, route, or other operating conditions create special circumstances warranting an increase.(f) The Commandant will consider reductions to the number of mates required by this section when special circumstances allowing a vessel to be safely operated can be demonstrated.(g) On vessels subject to STCW, the individual meeting the requirement of this section must also hold an STCW endorsement as officer in charge of a navigational watch with the appropriate tonnage for the vessel which he or she is operating, except as noted in § 15.105 (g) of this part for vessels on domestic near-coastal voyages.CGD 81-059, 52 FR 38652, Oct. 16, 1987, as amended by CGD 81-059, 54 FR 149, Jan. 4, 1989; CGD 81-059a, 55 FR 14805, Apr. 18, 1990; USCG-1999-6224, 64 FR 63235, Nov. 19, 1999; 66 FR 20944, Apr. 26, 2001; USCG-2006-24371, 74 FR 11262, Mar. 16, 2009; USCG-2004-17914, 78 FR 78005, Dec. 24, 2013; USCG-2012-0208, 79 FR 48924, Aug. 18, 2014