I used a Free 3D mountain terrain prop, created by shaiksha35, in OBJ file Mountain Free 3D Model - .3ds .obj .blend - Free3D .
I deleted the texture file from the mountain prop. I applied a Youtube video  to the mountain prop. I animated the mountain prop by raising it up for 100 frames, and  lowering it after 100 frames, and so on until the end of the video. I also used sound effect waves. The lightning I used a Youtube lightning video as a plane and put it in diffuse and opacity channel of lightning video plane. Then I used a glow map for lightning.  

Neat trick with the mountain terrain -- did you 'move' the mountain up and down, or did you 'scale' the height of the terrain up and down?  I was trying to figure out how some parts could be moving up while others were moving down -- did you use 2 copies of the terrain?

Reallusion Certified Director / Reallusion Best Visual Award / Reallusion Certified Content Developer
See all the G-Tools Plug-Ins available for iClone here: G-Tools Plug-Ins

I have one terrain. You know the scale tool. I just used the raised part (blue part of the tool) not the width or length of the tool. I went on timeline to 100, and raised the mountain. I went to 200 then lowered the mountain.
I did this until the end of video. That way, in the background, you see the peaks or waves above the horizon of the sea. Instead of looking like a flat plane video, it has depth, so you could light the peaks or waves.

Very clever, Michael 👌🏽