On 4 May 1945 aircraft of 846 Naval Air Squadron flew from Trumpeter to take part in Operation Judgement, an attack on the U-boat depot at Kilbotn, Norway, contributing eight Grumman Avengers and four Grumman Wildcats to a 44-aircraft attack that destroyed several vessels including the depot ship "Black Watch" and U-711.
Trumpeter was returned to United States' custody 6 April 1946, stricken from the Naval Vessel Register 19 June 1946 and sold into merchant service as Alblasserdijk (later renamed Irene Valmas). She was sold for scrap in Spain in 1971.
These ships were all larger and had a greater aircraft capacity than all the preceding American built escort carriers. They were also all laid down as escort carriers and not converted merchant ships. All the ships had a complement of 646 men and an overall length of 492inchesft3inchesin (ftin), a beam of 69inchesft6inchesin (ftin) and a draught of 25feet.[1] Propulsion was provided a steam turbine, two boilers connected to one shaft giving 9,350 brake horsepower (SHP), which could propel the ship at 16.5kn.[2]
Aircraft facilities were a small combined bridge–flight control on the starboard side, two aircraft lifts 43feet by 34feet, one aircraft catapult and nine arrestor wires.[3] Aircraft could be housed in the 260feet by 62feet hangar below the flight deck.[1] Armament comprised: two 4"/50, 5"/38 or 5"/51 Dual Purpose guns in single mounts, sixteen 40 mm Bofors anti-aircraft guns in twin mounts and twenty 20 mm Oerlikon anti-aircraft cannons in single mounts.[1] They had a maximum aircraft capacity of twenty-four aircraft which could be a mixture of Grumman Martlet, Vought F4U Corsair or Hawker Sea Hurricane fighter aircraft and Fairey Swordfish or Grumman Avenger anti-submarine aircraft.[1]