1...you can use this bitmap from b30 map named waves: or any other but I used it.

2...name the material (in this case waves) waves!$ and name the plane water!$

3...Apply the birmap like you woul anyother and you shuld get this: (dont mind the smiley....


4....export and all that stuff and you should get soemthing like this:

ok, if you can see it theres a hole there. Dont know why its there and dont know how to get rid of it. Hope to find out. Hope this helps.