Underwater scene plus lighting issues

[buggy]

I am trying to create a decent underwater scene (a few feet below the water in a freshwater river, with rocks and fish) and was wondering if anyone has any recommendations on how to best accomplish this using the Octane plugin.

Should I place a plane in the foreground with some kind of translucent material on it in order to make a mantle of slightly murky water in front of everything?
Or am I able to use something like fog to create the water.

Also, it seems that only the Octane Daylight produces an image. If I create an Octane Light or Octane IES Light all I get is a completely black render. Dialing up the strength makes no difference. I am using beta 3.00d.

Any suggestions will be much appreciated!