Upon being commissioned, "Windham Bay" underwent a shakedown cruise down the West Coast to San Diego, arriving on 6 June. She then briefly conducted air qualifications and catapult trials off the southern California coast, before taking on a load of aircraft and passengers bound for Hawaii. On 12 June, she left port, arriving within Pearl Harbor on 19 June, trading her cargo for another load, this time bound for the Marshall Islands. She left Pearl Harbor on 25 June, arriving at Majuro Atoll in the Marshall Islands on 2 July. She then sailed westwards to Kwajalein Atoll, also within the Marshalls. There, she took on the aircraft and personnel of Marine Night Fighter Squadron 532 (VMF(N)-532), and steamed for the Mariana Islands. The squadron arrived on Saipan, which had recently been secured, by flying off of her flight deck, and she put into Garapan anchorage to unload the squadron's gear.