Unsuspecting windsurfer collides with gray whale in the San Francisco Bay

Footage shows a man windsurfing being forcefully thrown from his board as a whale breaches off the California coast

An unsuspecting windsurfer collided with a gray whale on the San Francisco Bay in a startling and rare encounter captured on video.

The footage shows the moment the surfer is forcefully thrown from his board as a gray whale breaches off the California coast, plunging him into the water.