First up was making a base for each ship. I used an oval of balsa or basswood, sized to the ship as a base.
A Langton 20-gun brig is shown with a completed base.
For the water surface, I used Sculpy. I glued a goodly layer of Sculpy to each base, being careful to keep it a relatively uniform thickness of about 2mm.
It is really easy to get it thick in the middle and thin at the edges. To help avoid this, I usually turn the base over and press it onto a piece of paper. As seen, that makes it squish beyond the edge of the wooden base. That's OK, as the excess will be trimmed and sanded later.
Next, I took a little wad of crumpled tin foil and scarred the surface of the Sculpy. Less is more here. I tried to keep the scarring in parallel patterns, though.
Once the surface was scored, I pressed the hull of each boat into the Sculpy.
Some care needs to be taken when doing this step, in that the ship when built will probably be leaning off the wind as the sails carry the wind, so it helps to determine at this time which way your sails will be canted on the mast. Usually the molded-in fill of your spanker and jibsails determines this.
Off to the oven, where these were baked according to the instructions on the Sculpy box. When they came back, I took a knife and snipped off any plugs that stuck up. (If you do not do this, the ship will not sit in its own mold when finished, because the masts will fill the holes that created the plugs.)