Converted minesweeper and the first ship to carry the ASR designation. Before Widgeon, submarine rescue was improvised with whatever vessel happened to be nearby. She established a dedicated ship type whose sole purpose was standing ready to rescue crews from sunken submarines. The designation she inaugurated would persist for decades.

Lead ship of the WWII-era submarine rescue class, named for birds that could dive beneath the surface and return. Chanticleer and her sisters were purpose-built to carry the McCann Rescue Chamber, maintain a trained diving crew, and deploy to wherever submarines operated. In the Pacific, these ships stood ready at forward bases to respond if a boat went down.

Named for the coucal, a tropical bird. Carried the McCann Rescue Chamber along with heavy mooring equipment needed to hold position directly over a sunken submarine in open ocean. Rescue operations required anchoring precisely above the downed boat, lowering the chamber to mate with the escape hatch, and cycling survivors to the surface. Every minute counted.

Named for the florikan, an Indian bustard. Deployed to the Pacific where U.S. submarines conducted their silent war against Japanese shipping. Every submarine that sortied from Pearl Harbor, Midway, or Australia knew that an ASR was supposed to be standing by if something went wrong at depth.

Atlantic Fleet submarine rescue vessel. The Cold War made rescue more urgent than ever - nuclear submarines operated deeper and longer than their diesel predecessors. The McCann chamber had limitations, chief among them a maximum operating depth that submarines were beginning to exceed. Greenlet represented the best the Navy had, even as planners recognized something better was needed.

Last of the wartime Chanticleer-class. Named for the bird most associated with diving - appropriate for a submarine rescue vessel. Penguin and the other ASRs conducted regular rescue exercises with submarine crews, drilling the procedures that would be needed if a boat went down. The exercises were realistic and sometimes dangerous, because the alternative was discovering what didn't work during an actual rescue.

Built specifically to carry the Deep Submergence Rescue Vehicle - the answer to Thresher. Catamaran-hulled vessel designed around the DSRV mission, with a well deck between her twin hulls for launching and recovering the rescue submersible. The DSRV could dive to 5,000 feet, mate with a disabled submarine's escape hatch, and bring up 24 survivors per trip. A quantum leap from the McCann chamber's few-hundred-foot limit.

Second and final Pigeon-class ASR. With one ship in the Pacific and one in the Atlantic, the Navy maintained DSRV-capable rescue coverage across both oceans. The catamaran hull gave exceptional stability for launching and recovering the 50-ton DSRV in open ocean. Ortolan and Pigeon trained constantly with submarine crews, because a real deep-ocean submarine disaster was the one scenario where failure meant total loss.