Dozens of dolphins and sealions trained to detect and apprehend waterborne attackers could be sent on a mission to patrol a military base in Washington state, the US Navy said. It needs to bolster security at Naval Base Kitsap-Bangor, located on the Puget Sound close to Seattle. The base is home to submarines, ships and laboratories and is potentially vulnerable to attack by terrorist swimmers and scuba divers. Because of their sonar abilities, dolphins are excellent at patrolling for swimmers and divers. When it detects a person in the water, a Navy dolphin drops a beacon. This tells a human interception team where to find the suspicious swimmers. Sealions can carry in their mouths special cuffs attached to long ropes. If the animal finds a rogue swimmer it can clamp the cuff around the personâs leg. The individual can then be reeled in for questioning. The Navy has been training marine mammals since the 1960s and keeps about 100 dolphins and sealions.