What Is Reefing?
The staged reduction of a mainsail - with the universal answer to “when should you reef?”: as soon as it first occurs to you.
Reefing is the gradual reduction of a mainsail’s area: part of the sail is lowered and the reef points become the new attachment points. On a sailing boat, it is the safety adjustment; in the same wind, a boat that has been reefed will stand up better, go quicker and be less demanding to handle.
There is a reason for the old seaman’s saying: the moment you think about reefing is the moment to do it. Leave it too late and it turns into a crowded, stressful deck operation.
When and how
As soon as it first occurs to you: excess heel means not speed, but drag and heavier helm.
First, practise: a reefing setup that is tried for the first time in hard weather rarely passes the test; lines should be rehearsed in calm weather, in the marina.
Tightening lines: reefing lines running through boom blocks become stiff with poor maintenance, and that is often the reason people say the sail “won’t reef”.
The afternoon Etesian often builds through the day; planning your sail handling on the basis of “what will it be like by lunchtime?” is seamanship that saves effort later. Once a season, run a five-minute reefing drill with the crew; in hard weather, the difference is measured not in minutes but in safety.