Visitors on a whale watching cruise usually count themselves lucky to catch views of a fin or they're really lucky, a breach.
They don't expect to see hundreds and hundreds of dolphins leaping from the water, racing the waves over and over.
But that's exactly what happened to people who paid for a whale-watching excursion in Dana Point, California.
"Look at this -- unbelievable," a boat captain says as he watches the spectacle.
This dolphin behavior is called a stampede, though what causes it is unknown.
Organizers of the boat charter explained it this way: “It’s thought that the dolphins could be evading a predator such as orcas, racing to catch a food source, or meeting up with another pod of dolphins,” the charter operation said in an announcement of the encounter, noting the stampedes happen without warning or provocation.
They added that dolphins are not scared of the boat.