Hi Randy: We have not written about single line reefing in detail because we have not had a chance to use our system enough in heavy going to form an opinion. However, here is what we’ve learned in theory, with a small amount of practice thrown in.

1-If properly executed I think the system can work. But it is not totally foolproof.
2-We’ve talked with skippers of several boats in the 60′ to 80′ range that have the system and like it.
3-Handling the loads on the tack of the sail, which are inherent in a single line reefing system is now not a big issue. But of course, it has to be done correctly.
4-Positioning of the hardware at the forward end–this includes height of the tack ring–has to be done carefully, with an allowance for changing if the first time does not work out correctly.
5-Care must be taken with the lead of the reef line as it exits the forward, top end of the boom, so that the line can bend through various relatively unfair directions and not have a chafe problem.

All of the above issues are straight forward, and with a bit of fiddling, can be worked out. The issue that concerns me, with our system on Beowulf, is the bunching and/or binding of the sailcloth at forward and aft ends of the boom, as the sail is reefed down.

Beowulf has laminated Spectra/mylar/polyester sails–very efficient and light–but if they are crunched into a tight bunch the laminate will break down, so we need t be careful with the reefing process. This means that at the luff we have to take care to push the sail away from the side on which the block and reef line come down. With dual line reefing, this has not been an issue.

At the aft end you would think things remain the same between single and dual line systems. However, it appears so far that it is more difficult to control what happens aft with the single line system. One thing to note with any slab reefing system–avoid really snugging down the reef clew to the point where the sail cloth is overly bunched. It is better on the sail if the clew is left a little lose.

So far, with the few reefs we’ve taken in earnest, neither of these potential problems has been very serious. But, I am waiting for a couple of situations where we have to reef down in a sudden onslaught of wind, and then stay reefed for some time, before I make up my mind for sure. In the interim, we continue to carry our old dual line slab reefing system in reserve…just in case.

I think as you go smaller in boat size the issues are not as intimidating. If you go to single line–let us know how it works out. I’m sure you’ll get plenty of chances to use it around New Zealand!

Regards–Steve Dashew