How do most apply it?
Do you thin it if sprayed?
I am about to paint my boat and i am gonna spray it because i hate a roller and a brush.

I rolled my boat.

If you thin it, you will take away from it's density. Use a big nozzle. Spray ya boat with alum. Bright before painting. Letbit sit on alum for 15 or so minutes. Then rinse off

get some zinc chromate first then the paint

I don't know what kinda sprayer ya'll are using but that crap is so thick i could not get it to spray. I thinned a quart at the recommended thinning rate by duralux and still could not get it to spray through a gravity feed gun. So the thinned quart back with the rest of the gallon and broke out the roller and brush. That paint is more liquid vinyl.

I have been painting all week as well (both the zinc chromate stuff and the aluminum boat green). The Zinc Chromate stuff is harder to apply than the Aluminum boat green and Duralux seems to have the worst documentation in the industry even if their paint is good. I don't think I could have even painted if it was summer time (It was drying so fast). I have used all of their camo colors in the past, and I think the others went on easier than the aluminum paint but none of them were a pain like the zinc-chromate primer. Oh yeah, and Whizz Premium Velour rollers suck really really bad for Duralux. They completely disentegrate. Forget that they say they are ok for oil based paint.

I have a compressor and a gun with a 1.7 nozzle I have used for gel-coat before, but I did not even try it. Painting all the nooks and crannies with a brush (because you can't get in there even with a small roller) is such a PITA that I was wishing I had tried to spray. $700 for a pro job doesn't seem so bad now.

Sounds like the Duralux is very thick stuff. If you have real thick paint, an HVLP gun will not cut the mustard. Conventional airspray will, but you will have much more overspray and waste a lot of paint. As J and others have said, you will dilute the density (actually, the solids content by volume) if you thin the heck out of the paint.

I use Sherwin-Williams KEM 400, which is what many of the custom and production boat builders use. It's a bit of a PITA to get your hands on, as you must order it from a S-W Chemical Coatings specialty store, not your neighborhood S-W location.

KEM 400 will spray like hot butter through a properly set up HVLP gun with little to no reduction.