Sail handling

When and How to Reef a Sailing Boat

Published · Last checked October 2026

Reef the first time you think about it. Signs you are overpowered include constant heeling beyond about 20° to 25°, heavy weather helm, the leeward rail in the water and the crew struggling. As a rough guide many cruising yachts take a first reef around force 4 to 5 upwind. It is much easier to reef early, in harbour or before the wind arrives, than on a pitching deck.

A small sloop sailing upwind under mainsail and jib in a fresh breeze
Sailing upwind in a building breeze. If you are wondering whether to reef, reef. Photo: Ahunt, CC0.

Slab reefing the mainsail

A reefed mainsail showing the halyard eased to the reef mark, the luff cringle on the reefing hook, the reefing line pulling the new clew down and reef points round the loose sail
The four main steps of slab reefing.
  1. Brief the crew, then head up onto a close-hauled course or heave to, so the main de-powers.
  2. Ease the kicker (vang) and mainsheet; take the weight of the boom on the topping lift if you have one.
  3. Lower the main halyard to the mark for the reef.
  4. Hook or pull down the luff cringle to the tack and re-tension the halyard.
  5. Haul the leech reefing line tight until the new clew is down on the boom.
  6. Re-trim the mainsheet and kicker; tidy the loose sail with reef points round the sail only, not the boom.
A small cruising yacht sailing upwind under mainsail and jib
Headsail and mainsail need to come down in step to keep the boat balanced. Photo: Ahunt, CC0.

The headsail

Roller-furling headsails are reefed by easing the sheet and rolling some sail away, then moving the sheet lead forward if you can. Heavily furled sails set poorly, so a dedicated smaller headsail is better for serious weather.

Balance

Reef the main and headsail together to keep the helm balanced. Too much main gives weather helm; too much headsail gives lee helm and makes it hard to point.

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Frequently asked questions

At what wind speed should I reef?

It depends on the boat, but many cruising yachts take a first reef around 15 to 20 knots apparent wind upwind. Reef earlier with a new crew or at night.

Should I reef the main or the jib first?

Many yachts reef the main first to cut weather helm, then reduce the headsail to keep the balance. Check how your boat behaves.

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