USS Casco, a 1,766-ton Barnegat-class small seaplane tender, was built at the Puget Sound Navy Yard, Bremerton, Washington, and was commissioned in December 1941. She moved in May 1942 to the Aleutians, where her duties included surveying the islands and laying moorings for seaplanes as well as providing tender services. While at anchor in Nazan Bay in August 1942 Casco was torpedoed by the Japanese submarine RO-61. She was beached to prevent sinking and, after being refloated in September, underwent battle damage repairs and modifications at Puget Sound.
Casco returned to the Aleutians in March 1943 and in May particpated in the recapture of Attu. She left the Aleutian theater in November 1943 and, after repairs at Puget Sound, arrived in the Marshall Islands in February 1944. She tended seaplanes during the occupation of Majuro and Kwajalein, carried cargo during the buildup for the Philippine operations in late 1944, and supported not only seaplanes but also a squadron of motor torpedo boats during the Okinawa invasion in the spring of 1945. Casco returned to the West Coast in July 1945 for two months of upkeep. Her postwar activities included service in the Philippines between October 1945 and April 1946 and a brief period of training duty at Galveston, Texas. Casco was decommissioned in April 1947 and was loaned to the Coast Guard in April 1949. She served out of Boston, Massachusetts as the cutter Casco (WAVP-370, later WHEC-370) for the next twenty years. She was returned to the Navy in March 1969 and expended as a target in May 1969..
The third Casco (AVP-12) was launched 15 November 1941 by Puget Sound Navy Yard sponsored by Mrs. W. J. Giles; and commissioned 27 December 1941, Commander T. S. Combs in command.
After a period patrolling and caring for seaplanes off the northwest coast, Casco arrived at Sitka, Alaska, 5 May 1942 for duty surveying Aleutian waters, laying moorings for seaplanes, and providing tender services. Based at Cold Bay, she operated to Dutch Harbor Chernofaki Harbor, Kodiak, and Nazan Bay. While lying at anchor in the latter on 30 August, she was torpedoed by RO-6l. The resulting explosion killed five of her men, and wounded 20, but prompt and clearheaded action brought flooding to a halt and got the ship underway so that she could be beached and later salvaged. Casco was floated on 12 September, and after emergency repairs at Dutch Harbor and Kodiak, she received a thorough overhaul at Puget Sound Navy Yard.
Casco returned to fog-bound Aleutian duty in March 1943, operating at Constantine Harbor, Amchitka, as tender to Fleet Air Wing Four. In May she steamed to Attu, to care for the seaplanes conducting antisubmarine patrol and search missions in support of the Army's invasion of Attu. Here she remained providing the essential base for flights which guarded against further Japanese reinforcement or penetration of the Aleutians. The tender's service in these waters where weather was often as formidable an enemy as the Japanese ended in November, when she sailed for overhaul at Bremerton, Wash.
Casco arrived in the Marshall Islands in February 1944 to tend seaplanes of patrol squadrons at Majuro and Kwajalein during their occupation, and later at Eniwetok until September. Temporarily assigned to carry cargo in the buildup for the Philippine operations, she shuttled between Saipan, Ulithi, and the Palaus until November, then returned to tender duty, in the Palaus until January 45, and at Ulithi until April. After overhaul at Saipan, she arrived in Kerama Retto 25 April to care not only for seaplanes, but also for a motor torpedo boat squadron, all engaged in the Okinawa invasion and occupation.
Returning to the west coast in July 1945, Casco sailed back to the Far East in the spring of 1946 for operations in the Philippines, then served in training duty off Galveston, Tex. She was decommissioned 10 April 1947, and transferred to the Coast Guard on 19 April 1949.
Casco received three battle stars for World War II service.
"USS Casco (AVP-12) Summary Page"