what's it called?

Support Basics & Interface
1

When you see something under water and it appears distorted in the animation and is there a tut on it?

digiman

2

It’s called refraction, I think.

Here’s a tutorial:
http://download.blender.org/documentation/oldsite/oldsite.blender3d.org/99_Blender%20tutorial%20Refraction.html

3

Distortion of the appearance of objects in water (or any transparent medium) is caused by refraction of the light passing through. There’s a tutorial here about refraction in Blender, although I’m not sure how old it is. I’m sure there are others, too, you might try a forum search.

4

There’s no tutorial there just a picture.

digiman

5

Oops… sorry. I pasted the wrong link. :o

Here’s the right one. Also, here’s a different one.