Make Water Transparent?

I need to make water transparent, without losing the fx\water shader! Any help?

I've got a script for when you go underwater as well:

var fog = false;
var fogColor = Color (0, 0.4, 0.7, 0.6);
var fogDensity = 4;
var skybox : Material;

function OnTriggerEnter(other : Collider) {
    fog = true;
    RenderSettings.fog = fog;
    RenderSettings.fogColor = fogColor;
    RenderSettings.fogDensity = fogDensity;
    RenderSettings.skybox = skybox;

You need to add just one line in fx/water shader. In Pass statement( next line after “Pass{”) add “Blend SrcAlpha OneMinusSrcAlpha”. After that you can control opacity with alpha of HorizontColor property. You can also do it via script.