Bottlenose dolphin (Tursiops truncatus) jumping out of water, Navy Marine Mammal Program (NMMP), San Diego, USA. The NMMP trains dolphins and other sea mammals to perform underwater tasks such as detecting underwater mines, delivering equipment to divers, locating lost objects and guarding against intruders. Dolphins are highly intelligent animals and proficient swimmers, able to use echolocation to sense their surroundings. Although the animals are easily able to leap over the barriers of their pen into the open ocean, they freely remain in captivity. Dolphins are trained using food rewards for successfully completing tasks. The NMMP also trains California sea lions, killer whales and beluga whales.