For roller reefing you use a reefing strop. It's usually a strip of sail
material with a rope on the end. You take a tuck in the main and roll the
reefing strop into it.
The rope is tied off as a kicker (vang).
Adjust the size of the tuck in the sail to determine how high you want the
boom to be. Done properly, you will have a very flat efficient reef.
Disadvantage of roller reefing over slab: slow; takes two people for best
results (one for the roller, one for the tuck and strop)
Advantages: less kit; you can reef to any size; you can control the height
of the boom.
Personally, I moved to slab reefing when I bought a new mainsail, but roller
reefing has its place, particularly for dinghys, and I wouldn't knock it. Alisdair
