To furl or not to furl, that is the question. Even if you are sailing with a full racing crew you will need to consider handling systems to hoist and douse your reaching and running sails. These sail handling systems will make your experience smoother and easier.
Bottom-up furling systems work the same way that conventional headsail roller furling systems do. The tack is fixed to the drum at the bottom. As the drum turns, the tack winds around the cable or the structured part of the luff instead of an aluminum foil. The sail furls from bottom to top. Bottom-up units are perfect for the genoa-like AWA 40 and 60 reaching sails, as the top of the sail is not too wide. The mid-girth should be around 50 percent and generally no larger than 60 to 65 percent.
As downwind sails get bigger and the mid-girth increases, it becomes harder to get the top of the sail to furl if you start from the bottom. With top-down furlers, the head is attached directly to the swivel, and the tack is secured to a free-rotating fitting on the drum. As the furling line is pulled, the tack lags behind, and the sail furls from the head to the tack, capturing the hard-to-furl top sections first.
No matter how well the furling system works, it still has limits. Full-sized broad reaching and running spinnakers have mid-girths of as much as 100 percent and are very deep. Even with a top-down further, these spinnakers can be problematic to furl. As a rough guideline, if the mid-girth is over 88 to 90 percent of the foot length all bets are off − it might furl or it might not. A spinnaker sock is the better, more reliable option. In fact, it is also a good option for any full-sized asymmetrical spinnaker, even if you do have the ability to furl it. The cost-effectiveness of spinnaker socks is another plus for this option.