Reef Meaning in Sailing

To reef means to reduce the area of a sail, usually by folding or rolling part of it away, to maintain control in strong winds. Most mainsails have ‘reef points’ (rows of small holes) that allow the sail to be tied down to the boom at different heights. One specific example involves a sailor putting in a ‘first reef’ as the wind increases to 18 knots to keep the boat from leaning too far. Reefing early is a primary rule of seamanship, as it is much easier to do before the wind becomes too violent. A reefed sail is flatter and lower, which reduces the ‘heeling’ force on the boat. It is the most common way to ‘shift gears’ on a sailboat as the weather changes.