It's my firs time with water and i want to know what is the best product to make water.

Ahoy Filipe.

I like to use paintable silicone caulk for my waterline ships. After I put down a bit with the caulk gun, I spread it out with a paint stick (like frosting a cake) and then drag a foam brush in short strokes to make the waves. After it drys, I'll paint it. While the paint is drying, I trace the hull shape on a stiff piece of cardboard. I use the cardboard to cut out the silicone so I can place the ship on the base. Gel medium with white acrylic is used to make the wakes around the hull.

~Kenny