Mich. Comp. Laws § 421.21b

Sec. 21b. A seaman employed on an American vessel operating on the Great Lakes shall be entitled to benefits under this act. An offer of employment to a seaman need not be the individual's customary occupation under conditions of employment and remuneration substantially equivalent to those under which the individual has been customarily employed in such occupation. The term "seaman" as used in this section shall mean an individual who is employed as an officer or member of a crew on an American vessel.