The strength of the waves vary from calm to choppy, and changes in the strength of the waves will affect how your boat performs. Water is presented very effectively from a visual standpoint. At certain parts of the game when you are racing through shallow water, you can see objects at the bottom of the track including fish, sharks, and sunken ships. The boats are just as cool as the tracks. Each boat has unique physics for speed, cornering, turbo, etc.
Sound comes in to play here, as the engine on each boat has a distinct roar.
I have always thought that gameplay is more important than flashy graphics. Having said that, the Dreamcast version of Hydro Thunder is able to give you all great graphics and the great gameplay you would expect from the original coin-op version. There are plenty of small details for all of you people who love high quality graphics, and the Dreamcast doesn't seem to have too much trouble keeping the framerate high. There are occasional brief slowdowns in the framerate, and rare problems with clipping, but they don't seem to affect the gameplay. First of all, I have some problems with the way the user interface is implemented.