[2] Named for Gambier Bay on Admiralty Island in the Alaska Panhandle, she was originally classified AVG-73, was reclassified ACV-73 on 20 August 1942 and again reclassified CVE-73 on 15 July 1943; launched under a Maritime Commission contract by the Kaiser Shipbuilding Company, Vancouver, Washington on 22 November 1943; sponsored by Mrs. H. C. Zitzewitz, wife of Lieutenant Commander Herbert C. Zitzewitz, the Senior Naval Liaison Officer (SNLO) assigned to Kaiser's Vancouver Yard from the Navy's Bureau of Ships; and commissioned at Astoria, Oregon on 28 December 1943, Captain Hugh H. Goodwin in command.

To rally the workers, Kaiser initiated a campaign called "18 or More by '44" to meet the new challenge; being the 19th and last Kaiser-built carrier commissioned in 1943, Gambier Bay was dubbed the "Bonus Ship".

[3] She returned to San Diego via Pearl Harbor, ferrying aircraft for repairs and qualified carrier pilots off the coast of Southern California.

She departed on 1 May 1944 to join Rear Admiral Harold B. Sallada's Carrier Support Group 2 (TG 52.11), staging in the Marshalls for the invasion of the Marianas.

[4] Gambier Bay gave close air support to the initial landings of Marines on Saipan 15 June 1944, destroying enemy gun emplacements, troops, tanks, and trucks.

As her fighters prepared to take off, they found intense antiaircraft fire of the entire task group covering their flight path.

Gambier Bay remained off Saipan, repulsing aerial raids and launching planes which strafed enemy troop concentrations, bombed gun emplacements, and supported Marines and soldiers fighting ashore.

Gambier Bay continued close ground support operations at Tinian (19–31 July), then turned her attention to Guam, where she gave identical aid to invading troops until 11 August.

After a respite for logistics in the Marshalls, Gambier Bay spent 15–28 September supporting the amphibious attack which drove ashore and captured Peleliu and Angaur, Southern Palaus.

Powerful Japanese forces—composed of carriers, battleships, cruisers, and destroyers—attempted to converge on the Philippines in a three-pronged attack to the south, center, and north.

While steaming through the Sibuyan Sea en route to the San Bernardino Strait on 24 October, the Center Force was hit hard by hundreds of planes from the carriers of Admiral William "Bull" Halsey's Third Fleet.

However, shortly after sunrise on 25 October, a gap in the morning mist disclosed the pagoda-like masts of enemy battleships and cruisers on the northern horizon.

Visibility was approximately 40,000 yards (37 km) with a low overcast and occasional rain squalls which the American ships would use to their advantage in the coming battle.

Immediately, an urgent call for help went out from "Taffy 3" as the escort carriers steamed eastward to launch planes before gradually turning south to seek concealment in a heavy squall.

[6][7][8] Around 08:20, Gambier Bay was crippled by a shell hit which flooded her forward engine room, immediately cutting her speed to 10 knots as she gradually slowed until dead in the water 15 minutes later.

This achieved only partial success: Kongō engaged Heermann, but Yamato only engaged and helped to sink Hoel with her secondary battery and continued to pound Gambier Bay with her main battery, scoring another two hits at 8:37 which destroyed Gambier Bay's steering and fuel supply, followed by another hit at 8:43.

Gambier Bay was the only US Navy aircraft carrier sunk exclusively by surface naval gunfire during World War II, and one of only three worldwide (along with HMS Glorious in 1940 and IJN Chiyoda in 1944).