Weather and wind for boating

Here at, we like to talk about sailing as a mean of recreation, a hobby, or a theme for a vacation. This sounds – or at least we intended to make it sound – like a lot of fun. And it is. Beyond the fun, however, any sort of boating is also potentially dangerous. The most risky aspect of the sport is the weather.

Nothing is more important to consider when planning a trip this. Every time you are preparing to set sails, make sure that you have all the relevant information about the current wind situation and the weather forecast. In this article, we give you a concise guide on how to estimate your safety with respect to wind and weather.

The weather behaves differently in different parts of the World. If you are member of a boat club, check with others which sources they use to check local weather forecasts. There are also some good websites that can help you and for many countries and coats, national organizations offer wind reports that are specifically designed to meet the needs of sailors.

Wind is obviously the most important factor for sailors. Check on its direction and strength – wind indicators and tell-tales on your mast, boom and mainsail will help you for that. Wind and weather, however, can change quickly and a current situation sometimes doesn’t tell you anything about how the weather will be as little as an hour later. Always doubt your skills and ask yourself whether your experience is sufficient to stay safe under the given circumstances.

Sailors distinguish between offshore and onshore winds. Offshore winds blow from the land over the shoreline into the open sea – offshore. The area of the shoreline can be very calm, which high waves and strong winds further off on the open sea. This bears some danger especially for inexperienced crews. You might want to stay near the coast when you encounter offshore winds.

Look out for the wind, check the local forecast

Onshore winds blow from the sea to the land and hit you at the shoreline with full power. This means, that they are generally easier to predict. With onshore wind, it can be difficult to leave from the coast, however, as you might have to tack from the very beginning of your trip. Based on this distinction, you can then go ahead and think of the wind strength.

As you might have guessed, weather and wind were very common issues for sailors for centuries. Detailed knowledge about the weather could make a difference between survival and death, and good navigators were often well educated in meteorology. One tool that sailors use for more than 200 years is the so-called Beaufort Scale or the “Beaufort Wind Force Scale”.

Sir Francis Beaufort, an Irish hydrographer and admiral in the Royal Navy, developed this scale in 1806. It lists different strengths of wind and ranks them from 1 to 12. Originally, the scale described certain measures that were recommendable under certain circumstances. This part was changed several times as the scale became a standard part of log entries of the Royal Navy ships in the late 1830ies.

Ranking the wind for the sailor's need

The scale was later changed repeatedly and adapted over the course of the 19th century. Descriptions of sea and land conditions at different wind strengths were added to allow the scale to be used for a variety of applications beyond navigation. Nevertheless, the Beaufort Scale remained a key to wind observations for sailors and was standardized in 1923.

In modern meteorology, hurricanes are often scaled according to the Saffir-Simpson Scale, which is essentially an extension of the Beaufort Scale from 12 to 16 categories. In sailing, the Beaufort Scale is widely used all over the World to classify wind, although you might encounter country-specific variations especially in Asia. In the United States, gale warnings are announced at Beaufort 8 or 9, storm warnings follow at 10 or 11 and everything stronger is classified as a hurricane.

Finally, here it is, the Beaufort Scale in all its beauty. Read it and familiarize yourself with it. Print it and take it with you on your next trip to the coast. Quiz yourself and try to match your observations with the scale, and then check with the local weather authorities. In brief: practice to use the Beaufort Scale – generations of sailors ever since Victorian days can’t be wrong! It might safe your neck.

The Beaufort Scale

Nr Wind Speed Description Wave Height Sea Conditions Land conditions
kt km/h mph m ft
1 1-3 1-6 1-3 Light air 0.1 0.33 Ripples without crests Wind motion visible in smoke
2 4-6 7-11 4-7 Light breeze 0.2 0.66 Small wavelets Wind felt on exposed skin
3 7-10 12-19 8-12 Gentle breeze 0.6 2 Large wavelets Leaves in constant motion
4 11-16 20-29 13-18 Moderate breeze 1 3.3 Small waves Dust raised, small branches wave
5 17-21 30-39 19-24 Fresh breeze 2 6.6 Moderate waves, some spray Small trees sway
6 22-27 40-50 25-31 Strong breeze 3 9.9 Large waves with foam Large branches in motion
7 28-33 51-62 32-38 Near gale 4 13.1 Sea heaps up, foam Whole trees in motion
8 34-40 63-75 39-46 Gale 5.5 18 Moderately high waves, breaking crests, streaks of foam Twigs broken from trees
9 41-47 76-87 47-54 Strong gale 7 23 High waves with dense foam, crests roll over Light structure damage
10 48-55 88-102 55-63 Storm 9 29.5 Very high waves, sea surface white, visibility reduced Trees uprooted, structural damage
11 56-63 103-117 64-72 Violent storm 11.5 37.7 Exceptionally high waves Widespread structural damage
12 >63 >107 >72 Hurricane 14+ 46+ Huge waves; air filled with foam and spray, sea white Massive and widespread damage

Further Reading

Back to "sailing"

Marine Weather Links

Info on Foul Weather Gear

Wikipedia on weather

National Weather Service of the National Oceanic and Atmospheric Administration