Sails and UV protection
You can also use a UV protected dacron fabric in lieu of the sunbrella to protect your furled sail. Pros are it is a 5oz fabric as opposed to 9.5 oz for the sunbrella. (your sails are lighter for light wind conditions). Cons are the dacron fabric is only supposed to be good for 5 years as opposed to 10 plus for the sunbrella. But it can always be replaced.