Dolphins were first drafted into the US Navy in 1960 when scientists at the Naval Ordnance Test Center at China Lake, California, acquired a Pacific white-sided dolphin from a now defunct marine park in Los Angeles, naming her Notty after the weapons laboratory's acronym. They hoped that their studies of the dolphin's streamlined shape and superb hydrodynamic efficiency would provide them with clues for improving the design of torpedoes.

Suspecting that the land-based laboratory tank in which she swam was affecting her performance, the Navy scientists began searching for a larger testing site. In 1963, under the direction of the Office of Naval Research (ONR), a small research facility was developed alongside a coastal lagoon at Point Mugu, California, home of the Pacific Missile Range and Naval Missile Center. Additional dolphins were subjected to a battery of tests in an attempt to learn more about their sensory systems, deep diving physiology and sonar.

Testing eventually moved from the confines of the lagoon to the open ocean. On 13 August, 1964, the Navy's first open-sea release took place when a young female Atlantic bottlenose dolphin, named Buzz-Buzz, was released near Point Mugu. She came back upon command. Ten days later, a Pacific bottlenose called Keiki was released in the open sea. He had been trained to keep up with a small boat, and in a series of speed tests he reached a top speed of 31.4 kilometres per hour (19.6 mph).

According to Blair Irvine, who trained dolphins for the US Navy from 1965 to 1969, a key goal of the work at Point Mugu was to get the animals to perform as retrievers. 'We wondered if you could teach a dolphin to go out and find a sound-emitting pinger,' he said. 'We were told to test this idea with practice ordnance, as a demonstration. navy divers took a half hour to find one mine and put a line on it. We showed that a dolphin could potentially mark several mines much more quickly than that.'

Acoustic signals, usually a train of intense, broad-band clicks with maximum frequencies from two to four kilohertz were used as commands, and rewards of fish were given as positive reinforcement.

In August 1965, an irascible bottlenose dolphin, aptly named Tuf Guy or Tuffy for short, became the Navy's star pupil. Fresh from a successful series of tests aimed at determining deep-diving physiology, Tuff was flown to La Jolla, California, where the ONR was operating Sealab II, an underwater base 60m (200ft) below the surface. Tuffy was soon carrying tools and messages between the surface and the lab, delighting the news media in the process.

The impact of the Sealab II demonstration was considerable. Tuffy proved that it was possible to train a dolphin to perform tasks that would be impossible for a human diver. No human could have made the number of repeated dives in rapid succession that Tuffy did without suffering the 'bends'.

The lesson was not lost on the Navy's weapons-testing officials, who quickly enlisted Tuffy's aid in recovering equipment routinely lost at sea. These included the re-usable cradles which separate from Regulus missiles after firing from submarines and fall into the water, or unarmed nuclear anti-submarine rockets (ASROCs) launched from surface ships during tests. Before launch, these devices were equipped with acoustic beacons; Tuffy was able to home in on the beacons' signals and mark the location of the equipment which was then hauled to the surface by divers.

Tuffy's success inspired the Navy to try training two killer whales and a pilot whale to perform similar exercises but, despite some initial success, they proved expensive to feed and difficult to transport. As a result, they were eventually dropped from the programme.

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