goes the authentic route as he paints 
I wasn't sure what to do about the base. Normally, Dragon Turtles shows up in the middle of the sea. That limits the usefulness of the model for games, as not many games take place in the middle of the sea!
Luckily, that night I saw a program on TV about the Lake Champlain monster. I decided that Champ is actually a Dragon Turtle, and used a rocky beach of Lake Champlain for my base. This opens the model to more gaming possibilities, both fantasy and historical - French and Indian War, for example.
I have a bottle of white glue diluted with water at about a 50/50 ratio. I spread that glue all over the base, and dipped it in to a container filled with railroad ballast.
After that was dry (in a couple of hours), I painted the ground dark gray, and then drybrushed it medium gray, and then, very light gray.