46 CFR §11.433

1. (a)The minimum service required to qualify an applicant for an endorsement as Master of Great Lakes and inland self-propelled vessels of unlimited tonnage is—
   1. (1)One year of service as a Mate or First-Class Pilot while acting in the capacity of First Mate of Great Lakes self-propelled vessels of 1,600 GRT or more while holding an MMC endorsement as Mate inland or First-Class Pilot of Great Lakes and inland self-propelled vessels of unlimited tonnage;
   2. (2)Two years of service as Master of self-propelled vessels of 1,600 GRT or more on inland waters, excluding the Great Lakes; or
   3. (3)One year of service upon Great Lakes waters while holding an MMC endorsement as Mate or First-Class Pilot of Great Lakes and inland self-propelled vessels of 1,600 GRT or more. A minimum of 6 months of this service must have been in the capacity of First Mate. Service as Second Mate is accepted for the remainder on a two-for-one basis to a maximum of 6 months (2 days of service equals 1 day of creditable service).
2. (b)[Reserved]