Larger Boats with Fewer Crew
Furlers allow you to reef or stow the genoa from the safety of the cockpit instead of having to drag sails onto the foredeck. You can sail your boat shorthanded, or have your normal crew sail a larger boat. Even if the Vendée Globe Challenge isn't your idea of a vacation, remember that couples often take turns singlehanding while cruising.
Without the ability to reef easily, some sailors choose a relatively small headsail as their primary genoa. A tender boat might be fitted with a 125% number one genoa because the difficulty of changing down from a 155% genoa at 12 knots doesn't justify the enhanced light air performance. With an efficient reefing system, you can choose a primary genoa that's efficient in light air.
Of course, the genoa must be chosen with the prevailing conditions in mind. It will be heavier and smaller if your home port is San Francisco rather than near western Long Island Sound, but the sail can be designed for the lighter end of the wind range because reefing is easy. The design philosophy is similar to that used for mainsails: make it full-sized for light air because you can always reduce it when the wind comes up.
More Cabin Space
Few cruising boats offer convenient storage for unbagged sails; headsail changes involve packing the cabin with a sea of wet cloth that you can't properly stow until the boat is back in the harbor and the sail can be dried and folded. With a reefing system, you change and remove the genoa by rolling it on the headstay—there's nothing to stuff down the hatch that will crowd the cabin.
By their very nature, efficient genoas are cut close to the deck and obscure visibility ahead and to leeward. Since most sailing takes place within a few miles of a harbor, visibility can be important for safety and peace of mind. Resist the temptation to gain visibility by cutting the clew high and permanently reducing your sail area. You can simply reef the genoa a couple of turns when you're near a harbor, sailing at night, or approaching an area with navigational hazards.
The ability to reef the genoa means that you can slow the boat easily while retaining the ability to accelerate instantly when conditions change. Two examples of good times to slow down are when sailing through congested harbor entrances and making night approaches to unfamiliar harbors.
Reefing the genoa slows a boat and increases visibility. The rolled genoa is ready to deploy as you clear the harbor or channel.
There are those wonderful nights when the wind blows true and threatens to deliver you to a strange anchorage before dawn. Reefing allows you to tailor your ETA for a landfall after sunrise.Taking a knot or two off the speed throughout the night is more pleasant than parking in a seaway for a couple of hours waiting for daylight.
Sail More, Motor Less
How often do people describe their last cruise and not say, "we motored more than we sailed"? A furling system won't guarantee you'll always have wind, but it will make it easier to take advantage of what wind there is. The first few times the breeze starts to fill, the crew is happy to run the genoa up, but after the third or fourth time it dies, it's hard to convince the crew to abandon the bunk, the sun, or a good book and raise the sail. With a furling system, the helmsman can usually set the sail without encouraging mutiny.
Wind Range Flexibility
All-purpose reefing genoas cover the middle of the wind range very well, but there are times you need specialty sails for enhanced performance. Spinnakers and gennakers are easy to set with a furling system. After they are flying, the genoa rolls out of the way, ready for resetting before the spinnaker is struck. Every boat needs a heavy air jib for extreme conditions. Most sailors, particularly coastal cruisers, will reef the all-purpose genoa when the wind strengthens, but the heavy-air genoa is necessary because it offers efficiency in the upper end of the wind range. It's usually set before the boat leaves the mooring, but if the wind is already very high, start with the heavy-air jib and reef it if conditions deteriorate further.
Most sailors buy sailboats because they enjoy sailing and the skills that sailing demands. Unfortunately, most crucial maneuvers like docking, mooring, and anchoring tend to take place under power. A furling system acts like an automatic transmission; it makes slowing down and stopping much easier and allows you to practice boat-handling skills under sail.
Anchoring and mooring take place upwind and the mainsail can luff as you secure the boat. To set the anchor, it sometimes helps to force the main out to one side to stop the boat or start it drifting downwind. Reefing the genoa slows the boat to keep it under control.
Sailing off a mooring or anchor is simple with a furling genoa. After you're free, a small portion of the genoa can be released and held back to force the boat off on the desired tack. A reefed genoa allows you to sail the boat slowly and under control while the anchor is stowed. You may not moor or anchor under sail usually, but a furling genoa makes it much easier and you should develop these skills for the day the engine fails.
Sailing to a dock is more difficult because the final approach is not always upwind and you can't always let the main luff, but a furling system simplifies the maneuver. You can strike the main earlier and maintain control with the genoa.