Force 1 1 – 3 Knots. Light airs, Just ripples. Difficult to make way in a cruiser

Force 2 4 – 6 Knots. Light breeze, small wavelets. Still slow but possible to make a passage

Force 3 7-10 Knots. Gentle breeze, crests begin to break. Still using full sail.

Force 4 11 – 16 Knots. Moderate, small waves becoming larger. Frequent white horses (crests). Yachts with large sail areas might start to reef.

Force 5 17 – 21 Knots Fresh breeze Moderate waves of about 1 meter. Many white horses. Certainly reefing and enough wind for most cruising yachtsman

Force 6 22-27 Knots. Strong breeze, large waves, white foaming crests. Small headsails and well-reefed mainsails. Commonly known as a yachtsman’s gale.

Force 7 28-33 Knots. Near gale, sea heaps up, white foam, breaking waves blown in streaks.

Force 8 34 – 40 Knots. Gale, Moderately high waves, breaking crests, foam streaks. Storm sails
Fun on a 60 footer going down wind as above, but not so on anything smaller!

Force 9 41 – 47 Knots. Sever gale. High wave crests. Breaking tumbling sea. Vis, dramatically reduced by spray. Most yachts are not equipped or manned to cope here. Storm jib or no sails and a parachute anchor.

Force 10 45.55 Knots. STORM Very high waves with long breaking crests. Foam blown in streaks. I have experienced this weather once. It frightened the living daylights out of me. The sea is huge! A small boat is in great peril. Sorry but I have no pictures of such weather at sea. I am usually a bit busy to take pictures!

There are two more forces. Violent storm 11 and Hurricane force 12. We do experience these winds in the British Isles, but thankfully only very occasionally.