"Alvin"s first deep sea tests took place off Andros Island, the Bahamas, where it made a successful 12-hour, unmanned tethered test dive. On 20 July 1965 "Alvin" made its first manned dive for the Navy to obtain certification. On 17 March 1966, "Alvin" was used to locate a submerged 1.45-megaton hydrogen bomb lost in a United States Air Force midair accident over Palomares, Spain. The bomb, found resting nearly deep, was raised intact on 7 April. On 6 July 1967, the "Alvin" was attacked by a swordfish during dive 202. The swordfish became trapped in the "Alvin"s skin, and the "Alvin" was forced to make an emergency surface. The attack took place at below the surface. The fish was recovered at the surface and cooked for dinner. During Dive 209, on 24 September 1968 "Alvin" found an F6F Hellcat, #42782, 125 miles southeast of Nantucket. The aircraft had ditched 30 September 1944 during carrier qualifications; the pilot survived.