Short Answer: Not with the bf2 engine

Long answer: In bf2 the game draws water at a specific height as two (I beilve) planes (Flat rectangles) covering the entire map this height is contained within Watersettings.Con (and there for can be edited in note pad bf2 editor). The water can only be at this one height unless a second water plane (static object with all of the properties of water) is added. The top plane is the surface of the water, this is textured. The second plane slightly below the surface is untextured you see it when the camera turns on an odd angle in game (I am not quite sure of the purpose of this, it may be the collion mesh for water vehicles to stop them from sinking) The texture is added to the plane using an invisible static object called EnviroMap that makes the water become realistic looking andding texture and detail to the waters surface. The only wave effect built into the game is th animated ripple texture on the the top plane, this can be speed up or down by changing the Animation Speed variable in notepad or the editor. Waves could be added in the form of an animated staic using the code from the water planes, however the amount of waves required would cause serious lag on most compupters and may cause problems because of their changing collision mesh.

I hope this explains this situation in as much or as little detail as possible.

Would be impressive though. *Where did i put my surfboard*

General Un-Co,
                         Signing off