46 C.F.R. § 10.433 Service requirements for master of Great Lakes and inland steam or motor vessels of any gross tons.
Title 46 - Shipping
The minimum service required to qualify an applicant for license as master of Great Lakes and inland steam or motor vessels of any gross tons is: (a) One year of service as mate or first class pilot while acting in the capacity of first mate of Great Lakes steam or motor vessels of more than 1600 gross tons; or, (b) Two years of service as master of inland (excluding the Great Lakes) steam or motor vessels of more than 1600 gross tons; or, (c) One year of service upon Great Lakes waters while holding a license as mate or first class pilot of Great Lakes and inland steam or motor vessels of more than 1600 gross tons. A minimum of six 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 six months (12 months of service equals six months of creditable service).
Title 46: Shipping
PART 10—LICENSING OF MARITIME PERSONNEL
Subpart D—Professional Requirements for Deck Officers' Licenses
§ 10.433 Service requirements for master of Great Lakes and inland steam or motor vessels of any gross tons.

