Testing the Waters (Part 1/2) – Laying the groundwork for making water in a diorama

One vivid childhood memory I have was of me walking into a small hobby shop and being awe struck by the many World War II dioramas on display. One particular diorama grabbed my attention and just wouldn't let go because the modeller had constructed realistic looking water as part of the scene. To a little kid with no knowledge whatsoever of the hobby, the thought that something like that could be