When to reef? Sailing in strong wind

You should reef as soon as you first think about it, ideally before you cast off. Clear signs are strong heel, weather helm and heavy pressure on the helm. As a guideline, cruising yachts of 30 to 36 feet take the first reef at about 15 to 18 knots of true wind (4 to 5 Bft), earlier in gusty wind.

Why is the rule of thumb “reef early”?

Because reefing is easy in light wind and hard in strong wind. A reefed boat often even sails faster in strong wind, because it stands more upright and needs less rudder.

Shaking out a reef is always quick; putting one in at 25 kn on a wet, lurching deck is not. So tie in the reef in harbour or in the lee of an island, not in the first hard gust out at sea.

How can you tell it is time to reef?

From the boat itself: it heels a lot, develops weather helm and wants to round up into the wind, and the helm gets heavy. Out on the water, whitecaps, dark gust patches on the surface and shower clouds announce more wind.

• Heel: from about 20 to 25 degrees a cruising yacht usually loses speed and pointing ability; if the toe rail is in the water, there is too much sail up.
• Weather helm: you are constantly holding against it with a lot of rudder, and in gusts the boat rounds up into the wind (broach).
• The autopilot or helmsman can no longer keep up, and the boat runs unsteadily.
• The crew is getting tired, wet or nervous. That is a reason too.
• The forecast shows gusts above your boat's guideline value or a strong wind warning.

At what wind strength should you reef? Guideline values by boat size

The table gives guideline values for the true wind on upwind courses. Off the wind the boat can carry more sail a little longer. What counts is your boat's manual, the sails and your own experience.

You usually reef the mainsail first, because it drives the weather helm, and roll in the genoa to match so the boat stays balanced. A heavily furled genoa sets badly; from the second reef a jib or storm jib is better.

How do you prepare for strong wind?

Tie in the reef before you need it, put on safety gear, make the boat ready for sea and know a port of refuge. In strong wind, preparation in harbour matters more than skill out at sea.

1. Check the forecast, marine forecast and warnings, looking at gusts and waves, not just the mean wind.
2. Clear the reefing lines and have the storm jib ready to hand.
3. Put on lifejackets and harnesses and rig jacklines on deck.
4. Stow everything below, close the hatches and precook something warm.
5. Know ports of refuge that are safe to enter even in onshore wind.
6. Do not time headlands, tidal inlets and spots with wind against tide for the strongest phase.

What is heaving to and when does it help?

Heaving to means setting the boat with the headsail backed and the mainsail reefed so that it lies quietly at about 45 to 60 degrees to the wind and drifts slowly to leeward. That gives you calm to reef, eat, navigate or ride out the weather.

You tack without releasing the jib sheet, ease the main a little and lash the helm so that the boat wants to luff up (tiller to leeward, wheel to windward). You need open sea room to leeward for this. Practise the manoeuvre in moderate wind before you need it.

When are you better off staying in harbour?

When the gusts exceed the limits of boat or crew, a gale or thunderstorm warning is in force, strong wind is blowing onshore onto a coast without a safe harbour, or the crew is tired, seasick or inexperienced. A day in harbour costs nothing.

Particularly tricky are harbour entrances with breaking surf, tidal inlets with wind against tide and areas with downdraught gusts, such as under the Bora or the Meltemi. An overview of wind strengths is in the guide Wind strength and Beaufort.

How does Sailseer help with reefing?

For each leg Sailseer suggests a sail choice, calculated from the gust and the course to the wind. For a cruising yacht of 30 to 36 ft that means upwind: first reef in gusts over 16 kn, second over 22 kn, third reef with storm jib over 28 kn, and over 34 kn do not leave harbour; small boats earlier, large ones later. The rating checks the gusts against your boat's limit, and the wind alert notifies you by email or push when gusts above your threshold are forecast at your harbour. Plan a route with sail choice. Official warnings and marine forecasts take precedence.