I sprayed 2 pack on my old timber boat and it came up a treat, except for a bit of orange peel on one bow (temp of the air coming out of the compressor).
As Jeff said - Its all about the undercoat. I brushed on and sanded back 2 coats then sprayed a thinned 3rd coat to give an even white then the 1 top coat.
It didnt look as good as either of the Dunks boats, but it came up smooth and shiny and a winner in my eyes.

Trevor