|
fort No |
miles/hr (knots) |
/hr |
Seaman's
description |
|
sailing ship |
0 |
< 1 | <2 | calm | sea like a mirror | makes no headway |
1 |
1 - 3 | 2 - 5 | light air | ripples with the appearance of scales are formed but without foam crests | just has headway |
2 |
4 - 6 | 5 - 11 | light
breeze |
small wavelets, still short but more pronounced; crests have a glassy appearance but do not break | wind fills sails; makes up to 2 knots. |
3 |
7 - 10 | 12-19 | gentle
breeze |
large wavelets; crests begin to break; foam of glassy appearance; perhaps scattered white horses. | heels slightly under full canvas; makes up to 3 knots. |
4 |
11-16 | 20-30 | moderate
breeze |
small waves becoming longer; fairly frequent white horses. | good working breeze; under all sail; heels considerably. |
5 |
17-21 | 31-39 | fresh
breeze |
moderate waves; taking a pronounced long form; many white horses are formed; chance of some spray. | shortens sail |
6 |
22-27 | 40-50 | strong
breeze |
large waves begin to form; the white foam crests are more extensive everywhere; probably some spray. | double-reefs mainsail |
7 |
28-33 | 51-60 | moderate
gale (high wind) |
sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind; spindrift begins. | remains in harbour, or if at sea, lies to. |
8 |
34-40 | 61-74 | fresh
gale |
moderately high waves of greater length; edges of crests breaking into spindrift; the foam is blown in well marked streaks along the direction of the wind. | takes shelter if possible |
9 |
41-47 | 75-87 | strong
gale |
high waves; dense streaks of foam along the direction of the wind; sea begins to roll; spray may affect visibility. | - |
10 |
48-55 | 88-102 | whole
gale |
very high waves with overhanging crests; the resulting foam in great patches is blown in dense white streaks along the direction of the wind; the whole surface of the sea takes on a white appearance; the rolling of the sea becomes heavy and shocklike; visibility is affected. | - |
11 |
56-66 | 102-122 | storm | exceptionally high waves; small and medium sized ships might for a long time be lost to view behind the waves; the sea is completely covered with long white patches of foam lying along the direction of the wind; everywhere the edges of the wave crests are blown into froth; visibility affected. | - |
12 |
> 66 | >122 | hurricane | the air is filled with foam and spray; sea completely white with driving spray; visibility very seriously affected. | - |
.