Navigation knowledge 1. Calm or Force Zero No wind or zero wind: The wind speed is below Knot. When there is no wind, the sea is smooth like a mirror.

2. Light Air or Force One: The wind speed is between 1-3 knots. After the soft wind continues to blow for a period of time, the height of the Haibo wave will still be about 0.1 meters (0.25 å‘Ž), but many Rippers will be raised on the surface of the sea.

3. Light Breeze or Force Two Light or secondary wind: The wind speed is between 4-6 knots. After the breeze continues to blow for a period of time, there will be numerous small waves like small fish scales, but Crest will not break. The wave height is between 0.2-0.3 meters (0.5-1 ft). If it is under sunlight or moonlight, there will be sparkling scenery on the surface of the sea.

4. Gentle Breeze or Force Three: The wind speed is between 7-10 knots. After the breeze continues to blow for a period of time, there will be a Large Wavelet with a wave height between 0.6-1 m (2-3 å‘Ž). Some wave heads will start to crack, causing sparse and falling seas. White Cap appears.

5. Moderate Breeze or Force Four: Wind speed between 11-16 knots. After the wind has continued to blow for a while, the wave length of the sea wave will increase, and there will be many small white caps on the sea. The wave height is roughly between 1-1.5 meters (3.5-5 inches).

6. Fresh Breeze or Force Five Fresh or Five: The wind speed is between 17 and 21 knots. After the fresh winds continue to blow for a period of time, the sea will set off a medium wave with long wave lengths between 2 - 2.5 m (6 - 8 ft), and the sea will have a white cap that is not very dense. Appeared, and some of the white caps were still sprayed in the air by the wind.

7. Strong Breeze or Force Six: The wind speed is between 22-27 knots. After strong winds continue to blow for a period of time, large waves with sea-wave heights between 3-4 meters (9.5-13 inches) will appear. White cap waves can be seen everywhere, and Crest waves out of the waves due to the wind (Spray). White cap waves will be more.

8. Near Gale or Force Seven: The wind speed is between 28-33 knots. After the blast continued to blow for a period of time, the waves would rise straight up and the wave height would be roughly between 4-5.5 meters (13.5-19 inches). The white foam (Foam) generated after the breaking of the wave would start to be blown away by the wind. Not very thick blankets and/or not long pods.

9. Gale or Force Eight: The wind speed is between 34-40 knots. After strong winds continue to blow for a while, the sea will set off high waves with a medium degree and long Wavelength. The wave height is between 5.5 and 7.5 meters (18-25 ft). The waves will be blown into more detail by strong winds. Spindrift, the white foam that breaks from the top of the head, spreads out in blankets and/or ripples.

10. Strong Gale or Force Nine: The wind speed is between 41 and 47 knots. After the gale has continued to blow for a while, the sea will experience waves of heights between 7 and 10 meters (23 to 32 feet). The waves begin to roll violently, and a thick blanket of white foam will appear on the surface of the sea. Short, white, foamy, spindrifts may reduce Visibility.

11. Storm or Force Ten: The wind speed is between 48 and 55 knots. After the wind continued to blow for a period of time, the wave height would be between 9 - 12.5 meters (29 - 41 feet). The wave began to show the pressure of Mount Tai, and a large amount of blanket-like white foam appeared. The surface of the sea would appear paler and denser in the air. This will greatly reduce visibility. When a ship sails in a hurricane, it will roll out and pounding from time to time.

12. Violent Storm or Force Eleven: Wind speed between 56 - 63 knots. After the storm has continued for a period of time, the wave height will be between 11.5 - 16 meters (37 - 52 miles). The surface of the sea will not only have extremely rough waves, but will also be covered with thick carpet-like white foam, and the surrounding environment will be dark. Extremely poor visibility.

13. Typhoon or Hurricane Typhoon or Hurricane: Winds above Force Eleven are known as typhoons or hurricanes with wind speeds of 64 knots or more.