On 28 June 1918 SC-48 left New London, Connecticut in a convoy with 17 other submarine chasers, destroyer tender Bridgeport, and several other vessels, bound for France via Bermuda and the Azores.

At 06:40 on 5 August, as the convoy neared the Ushant Light, SC-48 spotted a torpedo wake headed for Bridgeport and sounded the alarm.

Bridgeport’s evasive action avoided the torpedo, and, despite reports of a periscope sighting, no submarine was ever located or sunk.

After the Armistice, Unit 20 took part in operations to clear the North Sea Mine Barrage through the end of September 1919.

By 1925, the ship had been renamed Stumble Inn 1 and was owned by Clarence Fix and based in Buffalo, New York.