The USS Mary Louise (SP-356) was a private vessel converted for military service as a patrol boat during World War I. Built at the Milton Point Shipyard in New York, she was originally constructed as a private boat before being acquired by the U.S. Navy. The Navy took possession of her on a free lease from her owner, J. S. Williams of Wilmington, North Carolina, on 24 August 1917, and she was officially commissioned as USS Mary Louise on 27 August 1917. Designed for patrol duties, the Mary Louise was assigned to the 6th Naval District, where she served on section patrol duties. Her role involved patrolling coastal waters and ensuring security during the wartime period. Given her brief service span, she was in active duty for approximately two months, effectively fulfilling her assigned patrol responsibilities during this critical time. Her service was relatively short, ending when she was returned to her owner on 30 October 1917, after which she reverted to private ownership. The USS Mary Louise’s service is indicative of the rapid mobilization and utilization of private vessels by the U.S. Navy during World War I, especially for coastal patrol and security roles. Although her active naval career was brief, her contribution exemplifies the wartime reliance on civilian vessels for maritime defense and patrol operations during a period of intense national security needs.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.