Ok, let's finish up. With a regular paint brush, doesn't really matter how wide it is 1" - 4" will work fine, put down a generous layer of clear gloss acrylic medium over the foam sea minus the section where your ship will sit.
Then, while this is wet, lay a single layer/sheet of paper towel over the sculpted foam. He cautions not to tear the paper if possible. Carefully press the paper towel into the wet foam area. He likes to use his fingers for this part but a sponge or soft brush would work to. The idea is to work out any bubbles that would get trapped underneath.
Now before the underlying layer dries, liberally put on more of the same medium you put onto the foam over the paper towel. Be careful not to brush or push too hard to avoid wrinkling the paper. He goes over it again with his fingers to push air bubbles from under the paper. What you want is a snug fit against the foam. No wrinkles... any wrinkles would spoil the realism of the waves. Set aside in a safe place, away from the cat and or pesky kids, and let dry.
When it is completely dry, trim the paper from the open space where your ship will sit and the outer edges of the base.
Next, apply several coats of artist's acrylic gesso on the surface. Gesso looks like white paint but kind of flows like a gell. Artists use it to make those fancy thick brush strokes and features you see on paintings. It would go under the paint on a painting, not on top.
Anyway, the trick with this stuff is to apply it with a brush going in line with the grooves. The brush marks should be going with the waves instead of against them. After more than twelve layers, you will notice that the texture of the paper towel disappear and the sea looks smooth. Let it dry and it is ready for paint. He states that he sands any debris out of the finish.
The base coat of paint he uses is a mixture of phthalo blue, black, and white acrylic paint. This would be artist paint in a tube. Mix it until it looks like the kind of ocean blue you want. I looked for phthalo blue with a green hue. The ideal color Chris Flodberg looks for he describes as denim.
Once this is on, look at your photo references of water around ships for where and how the foam is around the ship while it is moving. Guided by photos, he airbrushes dull, mint green to suggest subsurface churn created by the ship. I airbrushed this light, dull, mint green where the waves would be created from the bow cutting through the water, in the area where the resulting waves would be and in the prop wash area. All based on photos I had of the ship I was working on. The color Chris used is a mixture of white and turquoise with a tiny bit of black to dull the shade... when it looks good to you, let it dry. The nice thing about painting is if you don't like it, paint it over and start again.
Everything is then sealed with a clear flat acrylic to prevent subsequent layers from affecting the mint green.
Now for the fun part, the water effects. Chris used medical rayon balls (don't use cotton) and pulled the fibers apart between fingers to create webs. I couldn't get a hold of rayon balls so I used I used polyester fiberfill. This is the stuff used in stuffed animals or kid pillows. This thing is to pull it apart so that it is not in a clump. Clumps will come later in a way that you want them to be.
Carefully attach the fibers with Liquitex high-gloss varnish. This creates a watery clear, shiny finish. He describes the process like this, brush a little varnish onto the spot where you want to attach the fluff.
This would be like on the crest of a wave or somewhere the water surface would be bubbling like in the prop wash area. While it is wet, place the rayon web. Lightly applying more varnish over the strands causes the strands to bunch up and become coarser.
The result is very realistic as you can see from my earlier photos. Brushing on more varnish tamps the rayon onto the surface of the sea. I had to push my fibers down from time to time as the stuff dried. Then I would brush more on over the entire base. After several layers of the high-gloss varnish, you end up with what looks like real water.
Chris attached wooden blocks under his model so that the ship rode even at the waterline. Since the foam I used was only about 1/2" thick I just hot glued my ship into place and it sat right at the water line. You need to play around with your ship to get it to sit right in the water. Once you are satisfied with how it sits, glue or fasten it into place.
Next, patch the crack along the waterline with rayon and high-gloss varnish as described earlier. Here you would make the waves the bow creates pushing through the water and undulate the line along with water line. This would suggest motion through the water. When done. Let dry and sit back because not it is done.
Any questions? I think I may do a thread on how to do this later with lots of photos.