Under water distortion effects - A misunderstanding of optics?

I like to finally throw this question out to the community (Watching showcase video for Relief Terrain Pack asset was the last straw.)

What I have observed is found in a number of underwater effects from different packages and even from other engines such as cryengine.

Here is the question: Why are there distortion effects when the camera is underwater?

This particular distortion seems to defy the physics of light transmission. Distortion happens when light travels through two...

Under water distortion effects - A misunderstanding of optics?