The term “members of the armed forces”, wherever used in this chapter, means members in active service of the Army, Navy, Air Force, Marine Corps, Coast Guard, Space Force, Coast and Geodetic Survey, Public Health Service and Merchant Marine of the United States, and all regular and reserve components thereof. The term “members of the Merchant Marine of the United States”, wherever used in this chapter, means persons employed as officers or members of crews of vessels documented under the laws of the United States, or of vessels owned by the United States, or of vessels of foreign-flag registry under charter to or control of the United States, and persons enrolled with the United States for employment, or for training for employment, or maintained by the United States for emergency relief service, as officers or members of crews of any such vessels; but does not mean persons so employed, or enrolled for such employment or for training for such employment, or maintained for such emergency relief service, on the Great Lakes or the inland waterways. The term “United States”, wherever used geographically in this chapter, includes the territorial limits of the states of the United States and the District of Columbia.