The Avenger-class escort carriers were converted U.S. Maritime Commission (USMC) type C3 American merchant ships.

[3] She was converted to an escort aircraft carrier in the Tietjen & Lang shipyards New Jersey and commissioned into the Royal Navy on 2 July 1942.

Propulsion was provided by four diesel engines connected to one shaft giving 8,500 bhp (6,300 kW), which could propel the ship at 16.5 knots (30.6 km/h; 19.0 mph).

[2][5] Armament comprised three single-mounted 4-inch dual-purpose guns, two forward and one aft, and fifteen 20 mm cannon on single or twin mounts.

[5] She had the capacity for 15 aircraft which could be a mixture of Grumman Martlet or Hawker Sea Hurricane fighters and Fairey Swordfish torpedo bombers.

She participated in Operation Torch, with her sister ship Biter, carrying Sea Hurricanes of 804 Naval Air Squadron.

The death toll, 379 out of 528 crewmen, despite rapid response and assistance from ships and rescue craft from Brodick and Lamlash on the Isle of Arran and from Ardrossan and Greenock on the Scottish mainland, was amongst the highest in British home waters.

A section of this wood featured in the "Flotsam and Jetsam" exhibition in the Millennium Dome and another piece is held by the North Ayrshire Heritage Centre in Saltcoats.

The case is argued by authors John and Noreen Steele in their 2002 book The Secrets of HMS Dasher, however, this theory was disproved in 2010.