To eliminate the sunburn problem, many cruisers have a protective layer of Sunbrella about 18 inches wide sewn on the leech and foot. It looks like hell and does not improve the set of the sail. The better solution for a roller-reefing headsail is a cover of the kind I first saw on German yachts in the Baltic in the late ’90s and is now becoming common elsewhere. The cover, which is a long sleeve, is hoisted, usually with the spinnaker halyard, then tightened with a lanyard threaded through a series of hooks and eyes. It covers the sail completely and does not flap in the breeze. However, friction imposes a limit as to how big a sleeve can be made and still be practical to hoist and douse. Knight says the maximum practical luff length is about 60 feet.
A sail with a luff any longer than 60 feet is too big to regularly take down when the boat is not being sailed, so it is left up and the leech and foot remain exposed to UV rays. Some skippers, rather than use a colored protective material, have sacrificial strips of cloth the same color as the sail sewn on the leech and foot. Mark Fitzgerald, the longtime skipper of the 115-foot high-tech ketch Sojana, coats the leech and foot with white emulsion paint, which has proved to minimize UV damage. North Sails has a liquid “ink” that reduces UV damage. It is available in several colors and can be sprayed on existing sails if they are clean.