I have been using McCloskey's Spar. It was the first one I found that didn't have trouble drying on System 3 epoxy. Label says it's got UV protection but I have never found any varnish label that says exactly how much. After a year with 3 coats of McCloskeys on my canoes I am definitely looking for another product. 3 coats probably isn't enough anyway and the boats see a lot of exposure during the season but both boats were/are showing UV degradation in the epoxy after a year.