Some years ago, Asian Carp that were apparently caught in the holds and ballast water of ships and then discharged overboard, began to establish themselves in the inland waterways. They are aggressive when agitated by the sounds and vibrations of boats going by, and fly up into the air, sometimes landing on boats. The slapping sound they make when hitting the water is similar to jumping dolphins. Here are some photos and video of them following the boat.
M/V Leap of Faith 