A station tanker, her keel was laid down 11 October 1943 as SS Leif Ericson (MCE Hull 1930) by the Delta Shipbuilding Corporation in New Orleans, Louisiana.

She was named Porcupine on 23 October, launched on 24 November, accepted by the Navy 29 December; and commissioned the next day.

After shakedown in the Gulf of Mexico, the new Liberty ship was assigned mobile oil storage duties with the Service Force, Pacific Fleet.

By the end of November she was at Hollandia, New Guinea, and during the last days of 1944 she was a unit of resupply convoy "Uncle plus 15," which formed off Dulag, the Philippines, on 27 December and steamed up Leyte Gulf for Mindoro.

From 0330, 28 December, when the convoy entered Surigao Strait, until it returned to Leyte, it was either under air attack, or hostile aircraft were held on its radars.

The next day saw Leyte still blacked in, but Mindoro responded to Captain McLean's requests for air cover, and the convoy suffered no damage 29 December.

Gansevoort, surviving her hit, was towed toward the PT base at Caminavit Point and anchored in 15 fathoms of water.