How to Gauge Wind Speed When Sailing

Those sailors lucky enough (or wealthy enough, for that matter) to have electronic wind instruments have no need of guessing the wind speed. But every sailor should know how to gauge wind speed just by looking at the surrounding waters.

Instructions

Difficulty: Moderate

Things You’ll Need:

• Seamanship Books
• Pens
• Spiral Notebooks
• Binoculars
• Anchor Chains
• Anchor Lines
• Anchors
• Wind Gauges

1. Follow the Beaufort Wind Scale, which gives you wind ratings, a short term associated with that rating and a description of the effects observed on the water.
2. Look ahead, to the sides and behind you to get a 360-degree perspective on the wind.
3. Confer with other boats and your crew members, and discuss your observations.
4. Check the headsails in use by boats around you to estimate wind speed. A large No. 1 headsail likely signals 17 knots or fewer, a medium No. 2 headsail signals approximately 17 to 22 knots, a small No. 3 or "blade" signals 22 knots or more, and anything smaller is considered a storm jib for winds in excess of 30 to 35 knots.
5. Check for reefed mainsails. A single reef usually means near gale or gale force winds of 28 to 40 knots, and a double reef usually signals strong gale winds over 40 knots.

Tips & Warnings

• Buy a book that has a good Beaufort Wind Scale chart, and memorize the wind speed, its description and the observed effects on the water.
• Light air equals 1 to 3 knots and shows as ripples with the appearance of scales.
• Light breeze equals 4 to 6 knots and shows as small wavelets and crests of glassy appearance.
• Gentle breeze equals 7 to 10 knots and shows as large wavelets where crests begin to break.
• Moderate breeze equals 11 to 16 knots and shows as small waves of 0.5 to 1.25 meters with numerous whitecaps.
• Fresh breeze equals 17 to 21 knots and shows as moderate waves of 1.25 to 3 meters taking longer form with many whitecaps and some spray.
• Strong breeze equals 22 to 27 knots and shows as larger waves of 2.5 to 4 meters forming with whitecaps everywhere and more spray.
• Stay in if you can if winds approach gale-force strengths. At that point, sailing requires significant skill, physical and emotional stamina, and some luck on your side.
• Strong storm winds don't necessarily mean fun, faster sailing. Hundreds and perhaps thousands of boats each year are severely damaged or lost at sea in rough conditions.