Skip to main content

The Beaufort Scale: Classifying Wind and Sea Scapes


Created in 1805 by Britain’s Admiral Sir Francis Beaufort, the “Beaufort Scale,” which classifies wind and sea states according to a dozen different “force” levels, is widely used in the UK, but much neglected in the United States, which is too bad. Associating, say, a 15-knot “Moderate” breeze with such tangible effects as “numerous whitecaps,” gives a much better idea what 15 knots of breeze really means. It’s also a lot of fun. Take a few minutes to memorize the characteristics and wind speeds of a few different forces and then try figuring out how things stand next time you go sailing. There’s no better way of getting in touch with the wind and waves. Here is a list of the 12 different force classifications and their associated appearance on open water.

Force Wind speed Appearance of Wind/Effects


0 Calm 0-1 Sea surface smooth and mirror-like

1 Light Air 1-3 Scaly ripples, no foam crests

2 Light Breeze 4-6 Small wavelets, crests glassy, not yet breaking

3 Gentle Breeze 7-10 Large wavelets, crests begin to break, scattered whitecaps

4 Moderate Breeze 11-16 Small waves becoming longer, numerous whitecaps

5 Fresh Breeze 17-21 Moderate waves of 4-8ft taking longer form,

many whitecaps, some spray

6 Strong Breeze 22-27 Larger waves, whitecaps common, more spray

7 Near Gale 28-33 Sea heaps up, waves 13-19ft, white foam streaks

coming off breaking waves

8 Gale 34-40 Moderately high (18-25 ft) waves of greater length, edges of

crests begin to break into spindrift, foam blown in streaks

9 Severe Gale 41-47 High waves (23-32ft) begin to topple and roll over,

dense streaks of foam, spray may reduce visibility

10 Storm 48-55 Very high waves with overhanging crests, sea white with

densely blown foam, heavy rolling, lowered visibility

11 Violent Storm 56-63 Exceptionally high waves, foam patches cover sea,

visibility even more reduced

12 Hurricane 64-plus Air filled with foam, sea white with driving spray,

visibility greatly reduced

January 2021



Cruising: Safety Lessons Learned

It’s not often that sailors get a chance to put their rescue and MOB training to the test, rarer still that they do as quickly as newbie California sailor Khosrow “Koz” Khosravani did recently. If and when an emergency situation ever arises, though, it pays to be prepared. This more


At the Helm: Sailplans

The first thing you notice when you look at the sailplan for the Farr 65, Falken, which Mia and I recently added to the fleet here at 59-North, is the sheer number of headsails. Falken was built in 1999 as a racing boat to go around the world, and the crew would have carried the more


Racing Class Reunion

Where does an old VO70 go to retire? Right back to the racing circuit, apparently. This spring saw a remarkable contingent of Volvo Ocean Race one designs back on the water and duking it out on the Caribbean circuit. While it’s no surprise that some of the VO65 teams intending more


Charter: Sweden

With 2,000 miles of coastline, 270,000 islands and seemingly countless bays and inlets, Sweden is truly a sailor’s paradise. One of the top sailing destinations here is the archipelago just outside the country’s second largest city Gothenburg (locally known as Göteborg), on the more


Crowdsourcing Age-of-Sail Weather Data

Although big, multi-million-dollar projects like the Large Hadron Collider and the human genome project with their legions of PHD’s tend to grab headlines, there’s still a part of play for the “citizen scientists” of the world. Amateur birders have long contributed to an more


Ultims to Race Solo Around the World

For years now, maxi-trimarans, both solo-sailed and fully crewed, have been racing the clock on their own around the world in an effort to set ever faster records for the world’s fastest circumnavigation under sail. Back in 2000-01 there was also a no-holds-barred more


Juneteenth on the Water

Discovering Amistad and Mystic Seaport Museum have partnered to organize their third annual Juneteenth festival, featuring concerts, speakers and a reflection on the lasting legacy of racial injustice in America. Declared a National Holiday in 2021, Juneteenth celebrates the end more


New Multihulls for 2022

Lagoon 51 In keeping with many of the more recently launched models created by French multihull builder Lagoon, the Lagoon 51 is all about comfort, “en plein air,” in particular, as the French might say. Topside, a whopping 80 percent of the boat’s flybridge is given over to more