This is what happens when one dolphin and a thousand of its dolphin friends get together. It's called a stampede, or a "superpod" (like a pod of dolphin pods), and it is a rare and jaw-dropping sight to behold.
This particular superpod was witnessed just a few days ago from a whale-watching boat off the coast of California's Dana Point. Via the L.A. Times:
Dave Anderson, the captain of Capt. Dave's Dolphin and Whale Safari, said that in the decades he's spent on the water and out among Southern California's dense dolphin population, it's a phenomenon he's encountered only rarely.
"It's one of those things you can hope for it, but you can't plan for it," he said.
"It's one of the most amazing things I've ever seen, and I've seen a lot of beautiful and interesting things" on the water.
For good measure: here's another video of a superpod (also filmed in Dana Wharf) this one with close to 2,000 dolphins.