US Navy bottlenose dolphin (Tursiops truncatus). Animal trainer directing a bottlenose dolphin to swim in circles at the Navy Marine Mammal Program (NMMP), San Diego, USA. Dolphins are trained by the US Navy for a variety of underwater tasks, including detecting underwater mines, delivering equipment, locating objects, surveillance and guarding against intruders. Dolphins first saw active service during the Vietnam war in the early 1970s and most recently in Iraq in 2003. Dolphins are highly intelligent animals and proficient swimmers, able to use echolocation to sense their surroundings. The NMMP also trains California sea lions, killer whales and beluga whales.