The USS San Carlos (AVP-51) was a Barnegat-class seaplane tender constructed for the United States Navy during World War II. Laid down on September 17, 1942, by Lake Washington Shipyard in Houghton, Washington, she was launched on December 20, 1942, and commissioned on March 21, 1944. The vessel featured the typical design of her class, optimized to support seaplane operations in the Pacific theater. During her active service from 1944 to 1947, San Carlos participated in various operations across the Solomon Islands, Morotai, and the Philippines. She provided crucial air-sea rescue services and supported the deployment of floatplanes by fueling and tending to seaplanes, which were vital for reconnaissance and combat support. Notably, she shot down several Japanese aircraft—one on October 21, 1944, another on October 27, 1944, and a third on November 26, 1944—highlighting her role in defending Allied forces. Throughout her wartime service, she operated in key locations such as Leyte, Mindoro, and Cavite, contributing to the Pacific campaign's logistical and operational efforts. After the war, San Carlos was decommissioned on June 30, 1947, and placed in the Atlantic Reserve Fleet. She remained inactive until 1958, when she was reactivated and converted into an oceanographic research vessel named USNS Josiah Willard Gibbs (T-AGOR-1). Modifications included installing laboratories, a machine shop, a darkroom, and a deep-sea winch capable of handling extensive wire rope and equipment, enabling her to support scientific research. As Gibbs, she served as a principal research vessel for Columbia University’s Hudson Laboratories, focusing on ocean physics, including sound propagation studies critical to submarine and anti-submarine warfare. Her notable scientific contributions include surveying the Charlie-Gibbs Fracture Zone in the Atlantic and producing significant data for oceanographic research. She was in service until December 7, 1971, when she was stricken and transferred to the Greek Navy as Hephaistos (A413), serving briefly as a motor torpedo boat tender before being retired in 1976. The USS San Carlos thus holds a distinguished legacy as both a wartime seaplane tender and a key platform in oceanographic science.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.