We tested one-part poly on our deck, and it lasted about a week. I then went with Interlux two-part polyurethane, rolled, for the whole deck and cabintop, including the nonskid (we added particles for the nonskid sections). We''ve now used it for five seasons of pretty hard racing and cruising, and the paint is showing wear in spots where it gets chafed by lines and on corners here and there. I plan to spot-paint those areas in the spring. We avoided having to re-bed everything by masking the fittings as much as possible, but still ended up with spots on the winches etc.
It is a LOT of work. To put off having to do it again any time soon, use 2-part poly, get a good mask with a filter, and follow the directions scrupulously.