Built by: Electric Boat
Design: EB 213A
Keel laid: 6 October 1939
Launched: 28 September 1940
Sponsor: Mrs. W. R. Furlong
Commissioned: 31 March 1941
First Skipper: Lt. John F. Davidson

14 April 1942 at 2310, USS MACKEREL was proceeding on the surface down the American east coast from New London to Hampton Roads when the bridge lookout spotted what appeared to be two torpedo wakes headed for the submarine. MACKEREL quickly evaded and they claimed to have seen a U-Boat, so they fired two torpedoes from the stern tubes at the target. All torpedoes missed and contact was lost.

At 0503 the next morning, MACKEREL sighted a surfaced submarine and asked for a recognition signal. None was given, so one torpedo was fired. It missed and the target disappeared.

We have not been able to find anything in the German records to corroborate this action, so it is questionable if there was a U-Boat actually in the area and engaged with USS MACKEREL.

During this transit down the US east coast, USS MACKEREL was en route to a training base. She was designed as a training boat, and she spent the entire war in training – she saw no combat.

On 24 April 1947, USS MACKEREL was sold to North American Smelting in Philadelphia, Pennsylvania for scrap.