Is it possible to animate a terrain hmp or manipulate it's verticies with lite-C?

I'm trying to simulate waves on the ocean. I can to this with a normal model but my short range fog hides the faces of the model but not when I use terrain.

Its possible the manipulate the vertecies of a terrain directly,
its a slow approch tough, and better for just changing terrain
once (bomb crater or so)

You could also use multiple terrains that get turned on
one after another in a cycle. (more memory)

Not shure if there is an included terrain-animation setting now.

Better look for a better fog or whatever it is and use an animated model.

Sure, you can, using ent_setvertex, see details here:
http://www.conitec.net/beta/ent_getvertex.htm

It says that the first call will be slow, but fast at subsequent call(but that depends on how many vertex you want to deform I guess)
Or maybe using vertex shader will be faster...

ent_setvertex works like magic and is very fast. I've managed to make some great looking waves through direct manipulation. Thanks guys!

While I have your attention, does anyone know the fastest way to get a terrain height anywhere along it's surface?

terrain_height (ENTITY_T* terrain, VECTOR* position); only returns the nearest vertice and c_trace is a bit tricky to work with since I have multiple terrains in the game.

entity.floor_dist seems ideal but only shoots downwards and doesn't return the terrain pointer.

I need a very accurate method for the transition from underwater to above water on a moving terrain (water) with a second terrain representing the bottom/ground and an inverted object as the underwater surface.

I've tried c-trace on my animated terrain and it doesn't work! Even if I freeze my manipulated vertices the c_trace is not accurate at all. Very annoying!

You can displace the vertices using a vertex shader.