Sea Lion Soldiers
Special from the May issue of SuperScience
By Gail Hennessey

Zak leaps back into a boat following harbor patrol training with the U.S. Navy. Zak is a 375-pound California sea lion being trained to locate suspicious swimmers near piers and ships. (U.S. Navy Photograph by Photographers Mate 2nd Class Bob Houlihan)

Sea Lion Stats

  • Sea lions can see well in the dark and can dive to 650 feet.
  • Even when they're underwater, sea lions can tell where a noise is coming from.
  • These marine mammals are pinnipeds, meaning they have flippers-one pair in front and one pair in back.

A special U.S. Navy team has landed at an American port in the Persian Gulf. If members of the team spot an enemy, they send out a silent warning to sailors on board nearby ships. Who are these stealthy soldiers? They're sea lions—members of the Navy's Shallow Water Intruder Detection System program.

This team of sea lions has been trained to detect danger, such as a diver swimming too close to an American ship. The enemy diver could be planning an attack. The sea lions have been taught to swim quietly up to the diver from behind. Then they snap a locking clamp onto the intruder's leg or arm. Before the enemy knows what's happened, the sea lion has already darted away. In the meantime, human sailors pull on a rope attached to the clamp to haul the diver out of the water for questioning.

Other marine mammals, such as dolphins and porpoises, have helped our troops in past wars. But unlike dolphins, sea lions don't mind the warm waters of the Persian Gulf. And, if needed, sea lions can chase the enemy onto land!