134
7776 Last Resource
Beaufort
wind speed
Scale
appearance of the sea
description
(knots)
o
like a mirror
calm
less than 1
1
ripples with appearance of scales light air
1—3
but no foam crests
2
small wavelets, short but pro— light breeze
4—6
nounced; crests have a glassy
appearance but do not break
3
larger wavelets, crests begin to gentle breeze
7—10
break. Foam of glassy appearance.
Perhaps scattered white horses
4
small waves, becoming larger; fairly moderate breeze
1 1—16
frequent white horses
5
moderate waves, taking a more fresh breeze
17—21
pronounced long form; many white
horses (chance of some spray)
6
large waves; white foam crests are strong wind
22—27
more extensive everywhere (prob—ably some spray)
7
sea heaps up and white foam from moderate gale
28—3 3
breaking waves begins to be blown
in streaks along direction of wind
8
moderately high waves of greater fresh gale
34—40
length; edges of crests break into
spindrift; the foam is blown in well
marked streaks along direction of
wind
9
high waves; dense streaks of foam strong gale
41—47
along direction of wind; crests of
»
waves begin to topple and roll over;
spray may affect visibility
10
very high waves with overhanging whole gale
48—56
crests; resulting foam, in great
patches, is blown in dense white
streaks along direction of wind;
whole surface of sea takes on a white
appearance; rolling of sea becomes
heavy and shock—like; visibility
affected
I I
exceptionally high waves; sea com— storm
57—6 5
pletely covered with long white
patches of foam lying in direction of
wind; everywhere edges of wave
crests blown into froth; visibility
affected
12
air lled with foam and spray; sea
hurricane
over 65
white With driving spray; visibility
seriously affected