Section 11.433 - [Effective 1/17/2025] Requirements for Master of Great Lakes and inland self-propelled vessels of unlimited tonnage(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) 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 a License or MMC endorsement as Mate inland or First-Class Pilot of Great Lakes and inland self-propelled vessels of unlimited tonnage;(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) One year of service upon Great Lakes waters while holding a License or 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).