Here's a vintage video of Hydro Thunder on the Dreamcast. This was one of the better launch games for Sega's console in 1999; definitely one of my favorite water-racing games. It's an arcade port from Midway, very similar to their San Francisco Rush series of games.
I will definitely try to get my hands on this game later this week when I score another Dreamcast. It's an excellent racer that offers lots of fast and cheap thrills. The 2-player mode was a little rushed, and I always wished Midway would have made a sequel, but DC wasn't allowed to live long enough.
Ah, well, enjoy the video: