The ship was laid down by the Gulf Shipbuilding Corp., Chickasaw, Alabama as HMS Sepoy (BAM-30), renamed and reclassified USS Dextrous (AM-341), and launched on 17 June 1943; sponsored by Miss S. S. Kenney; and commissioned 8 September 1943.

On 21 January she left Naples for the Anzio-Nettuno beachhead where she swept mines prior to the assault the next day, and patrolled and provided anti-aircraft fire during the bitter fighting ashore.

Except for two voyages to Bizerte to replenish, Dextrous served off Anzio until 12 August 1944 when she sailed from Naples for pre-invasion minesweeping off the southern coast of France.

After calling at Guam to remove some experimental gear, she reached Okinawa on 14 July to join the minesweeping operations coordinated with the U.S. 3rd Fleet's final raids on Japan.

After the war Dextrous remained in the Far East, clearing minefields in Japanese waters until 15 January 1946 when she sailed from Sasebo, Japan, for the U.S. West Coast.