Hde.geocities.com/baerbel_beuse/mix_wind.htmde.geocities.com/baerbel_beuse/mix_wind.htm.delayedxYJ JOKtext/html8&'#Jb.HThu, 08 Nov 2007 15:24:00 GMTMozilla/4.5 (compatible; HTTrack 3.0x; Windows 98)en, *YJJ MIR - http://home.t-online.de/home/baerbel.beuse/

About the Weather at Sea

Wind

The windforce can be given in different ways: "Beaufort (Bft.)", "metres per second" or "knots", depending on whom you ask, captain, mate, able seaman... Trainees tend to look at the waves and say something like "if you see foam it must be 6" (6 what?!). So the best is to go to the bridge and ask there. Only problem is that they use different messuring systems, too. So you better ask what they use today. To make it easier to translate this now into the units you feel comfortable with see the following table:

 

Beauforts-Scale
wind force wind speed      sea  state    
        Bft          in m/sec       in km/h       in knots (nm/h)    waves (m)   
light air 1 0,3 - 1,5 1 - 5 1 - 3 1 calm-rippled
light breeze 2 1,6 - 3,3 6 - 11 4 - 6 2 smooth wavelets
gentle breeze 3 3,4 - 5,4 12 - 19 7 - 10 2,5 ...
moderate breeze 4 5,5 - 7,9 20 - 28 11 - 15 3 slight
fresh breeze 5 8 - 10,7 29 - 38 16 - 21 4 moderate
strong breeze 6 10,8 - 13,8 39 - 49 22 - 27 5 rough
near gale 7 13,9 - 17,1 50 - 61 28 - 33 6 very rough
gale 8 17,2 - 20,7 62 - 74 34 - 40 7 high
strong gale 9 20,8 - 24,4 75 - 88 41 - 47 7,5 ...
storm 10 24,5 - 28,4 89 - 102 48 - 55 8 very high
violent storm 11 28,5 - 32,6 103 - 117 56 - 63 9 phenomenal
hurricane 12 > 32,7 > 118 > 64 > 10 ...

Beaufort's wind scale from 1806

Of course you can, especially when at the helm, read the instrument yourself. But keep in mind that all instruments showing the windforce or direction can only tell the "relative wind" that hits the ship. To find out the "true" wind force it is neccessary in accordance to the course to either add (before-the-wind-courses) or substract (by-the-wind-courses) the speed of the ship, and to ask for streams and drifts that might influence, too. Too difficult? Well, you can always ask in the galley. The cook will tell you that if the pots get carried away from the oven we have storm...

 visibility:

The visibility of course influences sailing, too. Yes, we have a radar. But bad visibility can mean that for safety reasons the sails get stowed away and we proceed under engine.

 Sichtweite - visibility 
25nm excellent visibility 
10nm  very good visibility 
5nm good visibility
2nm moderate visibility 
1nm poor visibility
0,5nm very poor visibility 
500m moderate fog
200m fog
50m thick fog
< 50m dense fog


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