There's really no such thing as "low maintenance" painted wood. If there were, the vinyl siding people would be out of business.
My advice would be to forgo the paint and put on a good grade of marine spar varnish. Be sure and put the varnish on all surfaces of the wood, not just the exposed surface. Otherwise the wood will absorb moisture unevenly and the boards will warp. If you really want the black look, then I suggest applying a black aniline wood dye, then varnish. You probably won't find the analine dyes at your local hardware, but many places on the internet sell it. I buy mine from
Woodworker\'s Supply . Get the smallest quantity you can - it goes a looong way.
