It is not the number of coats, but the thickness of the coating that counts. This type of product can be sprayed easily with ordinary airless paint spraying equipment. Architectural acrylic elastomerics typically spec out at 10 dry mils per coat, which is .010".

It's pretty hard to measure the thickness of paint on a nonmetallic, nonrigid, curved surface. Wet mil gauges are available at most paint stores, they look like combs with stairstepped teeth, as in the pic below. You apply the coating, then dip the gauge in the wet paint, check which is the last tooth with paint on it, and read off the thickness as a mil number. Any curvature will throw it off though, so practice on a flat test panel to fine tune tip size, gun speed and overlap. It will take about 5 minutes to paint the boat. Don't waste your time trying to sand between coats though, it is like sanding a rubber eraser.

One other caveat too, use only piston pumps. Diaphragm pumps tend to cavitate because of the elasticity of the paint solids.