Using Mist

Hi,

I'm new to Radiance and this list. I am trying to create some sort of
underwater visualisation using Radiance. I have been told the Mist
material is the way to go with it or possibly a Mixfunc with Trans and
Mist.

I have tried experimenting with Mist and Trans, both with limited
success. Does anyone have any advice about how to achieve a realistic
model?

Cheers,

matt