Hoisting and Using If you've ever observed a racing crew hoist the headsail or mainsail aboard a boat before a race, you'll notice that there's always one or two people stationed at the mast to assist with the halyard. When these crew do the bulk of the work in getting the sail hoisted, that's usually known as bumping or jumping the halyard. Why do they do this? It's not simply a matter of getting the sail up quickly so that they can go sailing, it's principally because the longer the sail sits in that transitional stage between being trimmed and sitting idle, it will likely be flogging. Flogging is anathema for sails. The rapid shock loading that takes place when a sail flogs ensures accelerated degradation of the fibers that make up sailcloth and thus shortens the life span of a sail. Getting a sail hoisted quickly so the trimmer can get it trimmed works to reduce the time spent flogging, it's as simple as that.
Flogging is apt to occur at many junctures while sailing. Certainly it occurs momentarily when a boat is tacking or jibing, which is almost unavoidable. It's also likely to occur when a sail is lowered to the deck or rolled back up with its furling gear. Taking steps to lessen the time a sail spends flogging in these instances, or to lessen the degree of the flogging will ultimately translate into a longer effective life span for the sail.
The same logic applies when you temporarily put a sail away: the more care you take, the longer a sail will last. During a race when a crew changes headsails, it's rare to them actually stuff a sail down below without first flaking or folding it, but it does occasionally happen. Cruisers who aren't in a rush should take similar care if they're dropping a sail down on deck or putting it below, say to keep it from thrashing about in a passing squall. And by all means, if you have the sea room, turn your boat down wind to lower a headsail so that it will come down with relative calm as it sits blanketed by the mainsail.
Rolling and Flaking Properly stowing sails can help them last longer and maintain their shape longer as well, which is an important consideration for all performance sailors. Most racing sailors choose to roll their working sails when not in use. Rolling a sail allows it to be put away with little crimping or folding, which ultimately stress the fibers that make up the sail's cloth. When America's Cup ace Russell Coutts used to sail smaller boats (Finns and Solings in particular), he would always roll his sails over a cardboard tube and then put the whole deal inside a sail bag. That way his sails wouldn't be bent if they were being shipped or moved around.
If you roll sails that have battens in them—particularly full-length battens—keep in mind that you want the battens to be aligned with the lengthwise axis of the roll. If they end up twisted around the roll, and the sail is stored for a long period, the batten material may take on a memory of that twist and make it difficult for you to achieve the sail trim you're after once the sail is reused.
Flaking, of course, is another option for putting your sails away. The objective with flaking sails is to use gentle folds that allow the sail to be stacked upon itself. In the case of a mainsail where the luff is kept on the mast, you should use the natural turns of the luff between the slides as guides for subsequent folds. One note about battens, however, particularly full-length ones, don't allow them to twist or span from one side of the boom to the other. If battens are stowed like this for prolonged periods of time, they'll end up memorizing that shape and translating it into the shape of the sail, which will only hamper a sail trimmer's ability to get any productive shape out of the sail later on.
When flaking sails that aren't going to be kept on a spar, start at the foot with one person on the tack and one on the clew, and begin making even folds as you grab equal amounts of the luff and the leech and pull them toward the foot. Depending upon the cut of your sail, you may need to have one person make an initial fold before the other one starts so that the sail stacks uniformly.
If you're not going to remove the battens from the sail and you plan to simply keep it in a long bag ready to hoist again, it's a good idea to do what sailmakers term stacking the luff. That essentially means flaking the sail so that the luff sits folded on top of itself. If it's put away in that fashion, it will be lot easier to feed the luff into the luff groove of the headstay or to put the hanks on the headstay when you go to hoist the sail again.
A Few More Tricks
Here are a few additional practices that you'll want to adopt to ensure that your sails last as long as possible:
Releasing Tension—If you leave your headsail rolled up on its rollerfurling for prolonged periods of time, make sure you ease the halyard slightly so that the luff of the sail isn't under load during that time. The same goes for outhaul controls on mainsails that are left on the boom, along with cunninghams and leech and foot lines.
Stemming Flutter—You'll notice racing sailors won't put up with fluttering leeches on their working sails. They know this is counterproductive from a performance standpoint, but a 24-hour beat with a fluttering leech is equal to removing about six months of life from your sail.
Battening Down—If you allow your battens to continuously poke at their reinforcement patches, they'll eventually wear through the cloth of the pocket. When the sail isn't in use, take the time to alleviate the tension on the batten.
Drying Out—If you're in the habit of rinsing the salt off your sails after a long trip through the spray, make sure you also take the time to dry those sails; not by hoisting them at the dock but by spreading them out on deck for a little while.
Avoiding Snags—When it comes time to put a sail away, take pains to assure that you don't drag it along the dock, especially if it's a concrete dock or a wooden one prone to splintering. Other surfaces that are particularly wearing on sails include hot parking lots and gravel.
Blocking Sun—Most sailors know that UV radiation breaks down almost every kind of sail cloth, so keeping your sails covered when not in use is particularly important. If you can, keep the sails out of the sun's heat by removing them from the boat during down time.
Testing Your Sail Trim Knowledge by Brian Hancock
Considering a New Mainsail by Brian Hancock
Sail Care and Cleaning by Kathy Barron
Buying Guide: Headsail Sheet Lead Systems