One of the ways to make a more spectacular diorama is to add a water feature to it. One of the best at doing this is Gil Gonsoulin. I asked him what his secret was to making realistic water and he was very forthcoming about how he does it.
Making a diorama set in a watery environment starts with the surface of the base. You put the Matt Gel on first and then apply the paint. The paint tones will vary depending what water you are simulating. After the paint has dried, if you want waves you can use slow drying Gloss Medium Gel. Once this has dried go over it with more of the Gloss Gel – as much as you want. You can then shape it to make the waves while it is setting up.
To make the bow wake (or other similar water feature), glass angel hair is the best product to use to start the process. The newer angel hair just doesn’t work the same. Put the angel hair on a sheet of aluminum foil and coat it with the Glass Bead Gel medium. Flip it over, coat again, then hang it up to dry. At this time it can be shaped and applied to the surface of the water. Any gaps between the boat and the water can be filled using the with glass bead gel.
Churned up water can be simulated using White Opaque Flake Texture Medium.