First test run with the lights this morning. I still have A LOT of work to do such as 2nd coat of Drylok, lots of shading left to do, have to fill and sand some of the seams to smooth them out. But here is a pic with the lights set up behind the opening which will show you what I have had pictured in my mind to give it the whole "Underwater cave looking out to the open water" look I am going for.
First here are the lights I will be using. They will be a total of four of these led bulb (two for each opening). They are 20" long Cold Cathode lights which are used for lighting up computer cases in case modding hobby on computers. These have been converted over to normal household 110 power with inverters and a wall plug. The opening is covered with some light blue Christmas wrapping paper then the lights positioned behind it with a small space between the lights to focus the intensity more at the top of the opening so that it fades from top to bottom so it gives the effect of the water getting deeper the lower it goes in the opening...
Here is a pic with the lights on and the first of the two opening light up, and the room lights on as well.....
And a pic with the cave lights on and the room lights off....
And a close up...