I haven't thought about it in a great while, but years back, I had an older Sunnyfish that looked like it had been drug across Dead Mans Reef a dozen times. Not wanting to throw a lot of bucks at this little day project, I ended up with Rustoleum topside paint. Painted with a cheap brush only, it's fair to say it didn't flow just the way I would have liked. A drop of thinner, a better brush, rolling it on first, ALL would have probably produced a better result.
However, I too was not really gentle with Sunnyfish. Being more oriented at the big boat, I sailed this little boat HARD. And up on the banks or whatever else happened to be in front of a mean tack. Carried it back in forth in the back of a steel floored pick-up truck.
Now I skinned it here and there. Hell, I probably would have gouged it had it been made of stainless. But for the most part, really, that paint held up very well. Underwater even..