Although American warships had been actively engaged in patrol and escort missions in the Battle of the Atlantic even before Pearl Harbor, their techniques for combating the dangerous German U-boats were, in January and February 1942, still far from adequate.

Triton's antisubmarine warfare (ASW) training missions were conducted along with local patrol and escort duties out of Key West from 1941 into 1945.

On 9 June 1942, when SS Lake Ormoc reported an enemy submarine on the surface in her vicinity, Triton directed Thetis to make the search.

Triton attacked with depth charges but, after a further search, concluded that the target was probably a tidal rip in the Gulf Stream, not a submarine.

Triton's next recorded ASW operation came soon thereafter, during the concentrated search and destroy mission mounted to find the U-boat which torpedoed the American steamer SS Hagan on the night of 10 June.

The hunt, which involved radar-equipped United States Army Air Forces B-18 Bolo bombers, three destroyers, several PCs, and Triton and Thetis, took three days.

Triton took part in further attacks, along with the other ships of the hunter-killer group based on Key West; but, by that point, the enemy submersible had already been killed.

Reverting to Treasury Department control after the end of World War II, Triton was reclassified from WPC-116 to WMEC-116 (Medium Endurance Cutter) sometime in 1966.

She was sold as government surplus and converted into a twin-deck passenger excursion vessel for Circle Line Sightseeing in New York City.