There is nothing obvious in any file that I've found.
that includes the .act and .dll files.
I'd tend to agree with Anvart that it's all controlling the Camera view.
Games from the same era have no water like SH4/5
And shutting down the camera's ability to 'see' the objects makes more sense then
re-building the 3D object if one was to dip in and out of the water.
Remember the systems waaaaaaay back then?
They did not blow. Infact they did just the reverse!!