Wind & Weather
Wind has a name for every direction, and the boat has a name for every angle it can sail to that wind. Spin through the compass rose on the left; drag the boat on the right to see how its point of sail changes as it turns. Further down, learn to read the wind strength, the clouds and the barometer, so you can plan your sailing around the weather instead of being caught out by it.
Words you will hear on deck
Sailing has a precise vocabulary for wind and angle. These are the ones used constantly.
Windward & Leeward
Windward is the side the wind hits first – the upwind side. Leeward (“loo-ard”) is the sheltered, downwind side. Crew sit to windward to balance the boat.
Port & Starboard tack
You are on starboard tack when the wind comes over the starboard side (boom to port), and port tack when it comes over the port side. This decides right of way.
Heading up & Bearing away
Heading up (luffing) is turning the bow toward the wind; bearing away is turning it away. Cross the no-go zone bow-first and you tack; cross the wind stern-first and you gybe.
True vs Apparent wind
True wind is what you feel standing still. Apparent wind is true wind combined with the wind of your own motion – it is what the sails actually feel, and always comes from further forward.
Veer & Back
The wind veers when its direction shifts clockwise (e.g. S to W) and backs when it shifts anticlockwise (S to E). Veering often follows a passing cold front.
Gust & Lull
A gust (or “puff”) is a brief increase in wind; a lull is a brief drop. Sail the gusts by easing or heading up, and keep the boat moving through the lulls.
The Beaufort scale
Thirteen forces, from a mirror-flat calm to a hurricane. Drag the slider to see the sea state and what each force means for a small boat.
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What the sky is telling you
Clouds are weather you can see coming. High wispy cloud thickening and lowering is the classic warning of an approaching front and rain.
Cirrus
Wispy “mares’ tails”. Often the first hint of an approaching warm front – change within a day.
Altostratus
A grey sheet that veils the sun like frosted glass. Thickening altostratus means rain is on the way.
Cumulus
Puffy “fair-weather” clouds with flat bottoms. Small ones mean a fine day – but if they pile up tall, beware.
Stratus
Low, grey layer cloud – like a high fog. Dull skies, drizzle and poor visibility.
Nimbostratus
Thick, dark, shapeless rain cloud – the steady, soaking rain of a warm front.
Cumulonimbus
The thunderstorm cloud – a huge anvil-topped tower. Squalls, heavy showers, lightning and violent wind shifts.
Where air masses meet
A front is the boundary between a warm and a cold air mass. As one passes over you, the wind, cloud, rain and pressure change in a recognisable order.
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The barometer
Air pressure is the weight of the atmosphere, read on a barometer in hectopascals (hPa, the same as millibars). High pressure usually brings settled, fine weather; low pressure – a depression – brings wind, cloud and rain.
It is the trend that matters most. A steadily falling barometer warns that a depression and stronger wind are approaching; a rising barometer promises improvement. A rapid fall means it is coming fast – and will likely blow hard.
Buys Ballot’s law: in the northern hemisphere, stand with your back to the wind and low pressure lies to your left. Wind blows roughly along the isobars – anticlockwise around a low – and the closer the isobars are packed, the stronger it blows.