(1) American Great Lakes vessel 
The term American Great Lakes vessel means a vessel which is so designated by the Secretary in accordance with section 1241r of this Appendix.

(2) Great Lakes 
The term Great Lakes means Lake Superior; Lake Michigan; Lake Huron; Lake Erie; Lake Ontario; the Saint Lawrence River west of Saint Regis, New York; and their connecting and tributary waters.

(3) Great Lakes shipping season 
The term Great Lakes shipping season means the period of each year during which the Saint Lawrence Seaway is open for navigation by vessels, as declared by the Saint Lawrence Seaway Development Corporation created by the Act of May 13, 1954 (33 U.S.C. 981 et seq.).

(4) Secretary 
The term Secretary means the Secretary of Transportation.