Thousands of dolphins 'stampede' off California coast

The video, showing the dolphins swimming and leaping out of the water, was captured by a Newport Coastal Adventure crew member from a fast raft boat.

"Porpoising out of the water at a high rate of speed is the fastest mode of travel for dolphins because there is less resistance in the air than in water, which is why these dolphins move in this way when they're in a hurry," Jessica Roame, education manager for Newport Landing & Davey's Locker Whale Watching, said in a statement.

She said the dolphins could be trying to get away from a predator, searching for food or reaching another pod, although it's not entirely known why they behave this way.