She arrived the next day for duty with TG 27.1, training new escort vessels in antisubmarine warfare.

On 26 July 1945, while making a submerged practice approach on Chaffee (DE-230), she collided with SC-642 with slight damage to both ships.

On 20 October 1945 Marlin departed New London with Skipjack (SS-184) for Bridgeport, Connecticut, arriving that day.

Marlin was sold 29 March 1946 to the Boston Metals Company of Baltimore, Maryland, for scrapping.

Her sail at the time of the movie resembled Mackerel's; the forward portion was later cut back for a 20 mm Oerlikon gun platform.