Beaufort Wind Scale Developed in 1805 by Sir Francis Beaufort of England
Adapted by Tom Holtey for Tourers and Kayak Sailors alike. A table to help you estimate windspeed by observing the water conditions; or estimate water conditions by listening to windspeeds in weather reports.

1 Knot = 1.15 MPH

Beaufort
Force
Scale

Rounded to even figures:
Wind (MPH)

Original Beaufort Scale:
Wind (Knots)

Nautical Terminology

Appearance
On Water

Appearance
On Land

Notes

0

Less than 1.15

Less than 1

Calm

Sea surface smooth and mirror-like

Calm, smoke rises vertically

Best for beginners.

1

Up to 3.5

1-3

Light Air

Scaly ripples, no foam crests

Smoke drift indicates wind direction, still wind vanes

Easy for beginners.

2

Up to 7

4-6

Light Breeze

Small wavelets, crests glassy, no breaking

Wind felt on face, leaves rustle, vanes begin to move

Easy for beginners.

3

8-11

7-10

Gentle Breeze

Large wavelets, crests begin to break, scattered whitecaps

Leaves and small twigs constantly moving, light flags extended

OK for beginners.

Suitable for sailing.

4

12-18

11-16

Moderate Breeze

Small waves 1-4 ft. becoming longer, numerous whitecaps

Dust, leaves, and loose paper lifted, small tree branches move

OK for intermediate paddlers.

Best for sailing.

5

19-24

17-21

Fresh Breeze

Moderate waves 4-8 ft taking longer form, many whitecaps, some spray

Small trees in leaf begin to sway

OK for advanced sailing.

Advanced paddlers only.

6

25-31

22-27

Strong Breeze

Larger waves 8-13 ft, whitecaps common, more spray

Larger tree branches moving, whistling in wires

Small Craft Advisory is issued.

7

32-38

28-33

Near Gale

Sea heaps up, waves 13-20 ft, white foam streaks off breakers

Whole trees moving, resistance felt walking against wind

Paddlers should be off the water.

8

39-46

34-40

Gale

Moderately high (13-20 ft) waves of greater length, edges of crests begin to break into spindrift, foam blown in streaks

Whole trees in motion, resistance felt walking against wind

9

47-54

41-47

Strong Gale

High waves (20 ft), sea begins to roll, dense streaks of foam, spray may reduce visibility

Slight structural damage occurs, slate blows off roofs

10

55-63

48-55

Storm

Very high waves (20-30 ft) with overhanging crests, sea white with densely blown foam, heavy rolling, lowered visibility

Seldom experienced on land, trees broken or uprooted, "considerable structural damage"

11

64-72

56-63

Violent Storm

Exceptionally high (30-45 ft) waves, foam patches cover sea, visibility more reduced

12

73+

64+

Hurricane

Air filled with foam, waves over 45 ft, sea completely white with driving spray, visibility greatly reduced

Wave heights posted above are for open waters with considerable fetch. (Fetch is the distance that wind can blow over the water.) The longer the distance the wind blows across the water the higher the wave height can be. Strong winds blowing across a short distance of water will not produce sizable waves. Wind swell can be “surfed” with skill and the right boat, local “storm surf” is usually not preferred for regular surfing and wave riding. Small Craft Advisories are issued by the USCG and other boating authorities. While it is possible for expert kayakers to paddle in a SCA, all small boaters should make for land and/or stay off the water until the advisory is lifted.