I have a P4, 3Gighrz, 1 Gig Ram, Nvidia 6800GT computer. I can't understand why I would be having framerate issues at all with this game. I can run games like F.E.A.R. on high settings so BG&E should should fly on my system. However as soon as I am in the hovercraft in the open water my framerate drops drastically, so low that the game becomes unplayable.

I have the latest Nvidia drivers. Am I forced to drop AA, etc? Do I have to drop out of 1280 x 1024? I played this game on an Xbox and had no framerate problems and my computer is easily twice as powerful so what's wrong here?

Most likely you're encountering this problem:

http://forums.ubi.com/eve/forums/a/tpc/f/401101532/m/7861020533

Try disabling triple buffering in compatibility settings, if that doesn't help either set the water detail to low or try using the older 66.93 drivers.

Thanks for the tip. I think I had to disable triple buffer and drop water resolution to minimum to get it to work. Seems fine though I did encounter mismatched audio dialoge which I suppose is another problem. Guess it wasn't a very good port done to PC.

Even my xbox version seems to drop slightly when sailing around hyllis. I think thats meant to happen but I dont think its meant to be noticable.

Maybe your XB is toast.