A few years ago I made this (large) 1: 144 U-boat diorama. It is a combination of a harbor and a dry dock. The XXI boat is from Revell (the one with an interior, I had to close the open side of the boat) and both XXIII are from Trumpeter. The figures are by Noch and Preiser and the boats are by Artitec. The vehicles are converted Herpa. Lighting is built in.
The boats in the harbor
Water is yacht varnish. Several layers will create some dept in the water.
The effect of het varnish......a good shine...you see the reflections of the boats in the water.
the boat is supplied
See the reflections of the boats
A view from above
At the back you see an U boot motor. This was a left over of the Revell boat (because I did not use the interior)
U boats by night, in reality there would be darkness. (this is some artistic freedom :-)