OpenGL ES: Screen effect, like under water..

[ClaveMartin]

Hello all,

OpenGL ES:
I want to create a 'under water' kind of effect in my game app screen(full screen with water flowing, bubbles etc). I should create such thing using OpenGL ES. I am reading OpenGL contents from internet sites already, but couldn't find a way for my requirement. How to achieve this? What is the step by step procedure to achieve this? Could somone please give me hints?

Thanks.