My son and I used latex acrylic enamel porch and floor paint for his Ravenswood LV a couple of years back. I forget if his undercoat was 2 or 3 thin layers of grey, but I know that he had one small leak from a thin spot when we launched it grey. Since he has added the top 2 layers of purple and white he has had no leaks and the paint has stayed in place very nicely.
The local hardware stores no longer carry oil-based paints other than rustoleum, so we have been going with the acrylic latex enamel because of the better color selection.