I wouldn't use anything but spar varnish on my nets.

If you play around with this finish long enough you'll find that there are many benefits to adding oil as well as solvent and japan dryer to the spar varnish, in different ratios for different sequential coats in the finishing process of course.

Getting a sprayed or brushed coat to level nicely without sagging but obtaining enough build can be a bit of a tightrope act. Once you've got that proper wet coat applied you want it to "dry" fast enough to be dust proof. My nets have to hang to dry rather than being laid flat so runs can occur all too easily.

While this net varnish finish certainly doesn't buff out like a 3 week old NC lacquer finish it does respond very nicely to machine buffing after some curing time.

I've only had to refinish the "shovel" or bottom of the hoop portion of my nets because I use the fine nylon bag as an insect sein and place the hoop into the river bottom which is a bit tough on the finish after a few seasons. I have tried varnish over epoxy (only on the "shovel") to make the net bulletproof but the process is too expensive from a manufacturing standpoint.

Better details of nets: http://www.cflandingnets.com