Full-size seaplane tenders (AVs) were designed to support two squadrons of flying boats each, but they were more expensive to build and had a deep draft, precluding their use in shallow harbors.
In addition to carrying out the above-described responsibilities, they were well-enough armed to be employed as escorts for larger seaplane tenders, having a substantial anti-air and anti-surface gunnery capability, as well as depth charge racks and sonar for antisubmarine work.
Four of them were converted during construction to motor torpedo boat tenders, while a fifth was modified during construction for use as a catapult training ship for battleship and cruiser floatplane pilots, her catapult equipment coming from that manufactured for canceled Cleveland-class light cruisers.
The ships entered service between 1941 and 1946, and all but three of them were commissioned in time to participate in combat actions in World War II.
[3] The combination of the post-World War II downsizing of the U.S. Navy and the decline of the seaplane and motor torpedo boat in U.S. naval operations meant that all but the newest ships decommissioned in 1946 and 1947.
Eighteen were transferred to the United States Coast Guard – where they became known as Casco-class cutters – between 1946 and 1949 for service mostly as weather reporting ships, a role they played until the late 1960s and early 1970s; some of the Coast Guard ships saw service in the Vietnam War, and one survived as a cutter until 1988.
The murky information available on a unit incorporated into the Vietnam People's Navy after the fall of South Vietnam in 1975 suggests that she remained active until at least 2000 and may remain active today; even if reports of her longevity are inaccurate, the last member of this large and long-lived class of ships did not leave service until 1993, when the ship transferred to Italy was decommissioned by the Italian Navy.
[7] Humboldt was in commission from 1941 to 1947, performing her World War II service in the Atlantic and Mediterranean, where during the Natal Conference, she flew the Commander-in-Chief's flag.
[14] Oyster Bay was one of four Barnegat-class ships to be converted during construction into a motor torpedo boat tender.
She was in commission from 1943 to 1946, performing her World War II service in the Pacific, where she saw action in the New Guinea and Philippine campaigns.
She was transferred to Italy in 1957, serving in the Italian Navy until 1993 as the special forces tender Pietro Cavezzale (A 5301).
[17] Unimak was in commission from 1943 to 1946, performing her World War II service in the Pacific through the end of 1944, then in the Atlantic during the first half of 1945.
[18] Yakutat was in commission from 1944 to 1946, performing her World War II service in the Pacific, where she supported the Peleliu, Mariana Islands, and Okinawa campaigns.
[19] Barataria was in commission from 1944 to 1946, performing her World War II service in the Pacific, where she saw action in the Philippines campaign.
[20] Bering Strait was in commission from 1944 to 1946, performing her World War II service in the Central Pacific, where she saw action in the Okinawa campaign.
[22] Cook Inlet was in commission from 1944 to 1946, performing her World War II service in the Pacific, where she served in Hawaii and saw action in the Iwo Jima campaign.
She was recommissioned in 1951 and saw service in support of United Nations forces in the Korean War (1950–1953), then remained in commission until 1966.
In 1958 she was transferred to Norway, where she served as the Royal Norwegian Navy cadet training ship HNoMS Haakon VII (A537) until 1974.
[34] Onslow was in commission from 1943 to 1947, seeing World War II service in the Central Pacific, Palau Islands, and Okinawa campaign.
[35] Orca was in commission from 1944 to 1947, performing her World War II service in the New Guinea and Philippines campaigns.
[36] Rehoboth was in commission from 1944 to 1947, performing her World War II service in the United Kingdom and Brazil.
[37] San Carlos was in commission from 1944 to 1947, performing her World War II service in the Pacific, where she saw action in the Solomon Islands, at Morotai, and Philippines campaign.
After years in reserve, she returned to U.S. Navy service in 1958 as the hydrographic survey ship USNS Josiah Willard Gibbs (T-AGOR-1), serving in this role until 1971.
In 1971 she was transferred to Greece, where she served in the Hellenic Navy as the motor torpedo boat tender Hephaistos (A413) until 1976.
[38] Shelikof was in commission from 1944 to 1947, performing her World War II service in the Central Pacific and in the Okinawa campaign.
[40] Timbalier was in commission from 1946 to 1954, performing most of her active service in the Caribbean and along the United States East Coast.
She was in commission from 1944 to 1946, performing her World War II service in the Pacific, where she saw action in the Philippine and Borneo campaigns.
Upon the collapse of the South Vietnamese government at the end of the Vietnam War in 1975, she fled to the Philippines, and served in the Philippine Navy until 1985 as the frigate RPS (later BRP) Gregorio del Pilar (PF-8) and from 1987 to 1990 as the frigate BRP Gregorio del Pilar (PF-12).
She was in commission from 1944 to 1946, performing her World War II service in the Pacific, where she saw action in the Philippine and Borneo campaigns.