The senior officer present afloat in foreign waters shall send to the United States by Government or other transportation as soon as possible each enlisted member of the naval service who is serving on a naval vessel, whose term of enlistment has expired, and who desires to return to the United States. However, when the senior officer present afloat considers it essential to the public interest, he may retain such a member on active duty until the vessel returns to the United States.

The substance of this section shall be included in the enlistment contract of each person enlisting in the naval service.