How to make water you can see through.

1. Make a room with a hole in the ground (Screenshot 2)

2. Choose the !WATERBLUE texture and brush in the hole. (Screenshot 3)

3. Rightclick the water and chose tie to entity.

4. Choose func_water and use these settings: (Screenshot 1)

Render Mode > Texture - some light
FX Amount > 50-100

5. Close, add some light and spawns and compile.

Then you are done... Look at screenshot 4 if you want to look at the result.

screenshot 1:

Screenshot 2:

screenshot 3:

screenshot 4: