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How the Beaufort Scale Affects Your Sail Plan

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How the Beaufort Scale Affects Your Sail Plan How the Beaufort scale affects your sail plan The Beaufort scale is a measurement that relates wind speed to observed conditions at sea. Used in the sea area forecast it allows sailors to anticipate the condition that they are likely to face. Modern cruising yachts have become wider over the years to allow more room inside the boat when berthed. This offers the occupants a large living space but does have an effect on the handling of the boat. A wide beam, relatively short keel and rudder mean that if they have too much sail up they have a greater tendency to broach into the wind. Broaching, although dramatic for those onboard, is nothing more than the boat turning into the wind and is easy to rectify by carrying less sail. If the helm is struggling to keep the boat in a straight line then the boat has too much ‘weather helm’ i.e. the boat keeps turning into the wind- in this instance it is necessary to reduce sail. Racer/cruisers are often narrower than their cruising counter parts, with longer keels and rudders which mean they are less likely to broach, but often more difficult to sail with a small crew. Cruising yachts often have large overlapping jibs or genoas and relevantly small main sails. This allows the sail area to be reduced quickly and easily simply by furling away some head sail. The main sail is used to balance boat as the main drive comes from the head sail. Racer cruisers will often have smaller jibs and larger main sails, so reducing the sail area means reefing the main sail first and using the jib to balance the boat. Every boat is different- if you own your own boat experience will allow you to know what sail plan works best. This worksheet is designed to give practical advice on the type of sail plan that should be used as the wind increases in strength, allowing you to reef and prepare your sail plan in port before you go out. It is intended as a guide only as there are numerous boats with numerous different sail plans specific to each boat. Please visit our worksheet on reefing for further information on how to reef. REMEMBER it is always easier to shake out a reef than to put one in, and if you think you should reef, reef. If you are thinking about shaking out a reef, put the kettle on and have a cup of tea, as often the wind picks back up again. V1.0 www.equinoxsailing.com [email protected] Force 1 – Light airs Sea State - Ripples Wind Speed – 1-3 knots Sail plan – normally under engine as not enough wind to sail Force 2 – Light breeze Sea State – Small Wavelets Wind Speed – 4-6 knots Sail plan – Full mainsail and large jib or genoa Force 3 – Gentle Breeze Sea State – Occasional crests Wind Speed – 7-10 knots Sail plan – Full mainsail and large jib or genoa Force 4 – Moderate Breeze Sea State – Frequent white horses Wind Speed – 11-16 knots Sail plan – Full mainsail or consider reef 1 and reduced headsail Force 5 – Fresh Breeze Sea State – Moderate waves, many white horses Wind Speed – 17-21 knots Sail plan – Reef 1, consider reef 2 in main sail and reduced headsail Force 6 – Strong Breeze – Strong wind warnings Sea State – Large waves, white foam crests Wind Speed – 21-27 knots Sail plan – Reef 2 main sail and reduced headsail or heavy weather jib. We have only gone up to Force 6 in this guide as sailing in Force 7 and 8 winds requires a third reef in the main sail or storm main sail and a storm jib. All Coded boats that are available to charter will have sails suitable for these conditions. Sailing in gale force winds is difficult and challenging and it is ill advised to set out knowingly in these conditions. If your passage is primarily sailing into the wind you may find having a more conservative sail plan easier. It you are sailing off the wind or downwind then you will be able to carry more sail, however it is prudent to reef the boat so it would be comfortable if sailing close to the wind. If you have a furling jib then increasing or decreasing the amount of sail you have is relatively easy, so reef the main in port. If your course is downwind then why not consider just the jib. It reduces the risk of gybing and will put less pressure on you as skipper and your crew. V1.0 www.equinoxsailing.com [email protected] .
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