While Trumpeter was completing outfitting at New York Navy Yard only three days after her commissioning, sparks from a workman's burner set off a small fire on a line between the dock and the port side of the ship.

Antisubmarine runs, practice fueling at sea, towing, mail-passing and emergency steering drills readied the new destroyer escort and her crew for the rigors of wartime Atlantic operations.

The same day, she moored at Naval Air Station Quonset Point and reported for temporary duty with the Antisubmarine Development Detachment, Atlantic Fleet (ASDEVLANT).

After repairs to one of her main propulsion generators, she resumed her duties at Quonset Point, Rhode Island, remaining there until 13 February when she detached from ASDEVLANT and made way for New York.

The escort carrier hunter-killer group was an innovation in antisubmarine warfare which effectively blunted the efficiency of German submarines in the Atlantic shipping lanes.

The two DE's picked 23 Germans from the waters, but the flier, whose bold low altitude bombing run had finished off the U-boat, was still missing when the search was ended.

Trumpeter's routine of patrol interspersed with periods of repair and upkeep was varied in August with four days of antisubmarine exercises and night battle practice out of Recife.

Arriving at New York on 13 October, she commenced 30 days of availability and drydocking; then, on 14 November, she set her course for South America, conducting firing practice as she steamed southward.

On 24 April, while patrolling off the New England coast, she struck an underwater object which damaged her sonar gear, making it necessary for her to detach from the task group (TG 22.6) and put in at Norfolk, Virginia, for repairs.

Underway again on 23 July, she set her course for the Caribbean and, on the 27th, arrived at Guantanamo Bay for refresher training in gunnery, antisubmarine warfare, damage control, and shore bombardment.

She arrived at Pearl Harbor on 2 September and alternated exercises with carrier rescue duties until late in October when she began weather station patrols in the North Pacific.

She arrived at Boston early in January 1946 and remained in East Coast ports until February when she reported to the U.S. 16th Fleet at Green Cove Springs, Florida, to await inactivation.