8 Explanation of the terms apparent wind, true wind and
VMG
See the diagrams below.
Figure 1:
Ship sailing against the wind
Figure 2:
Ship sailing with the wind
AWS:
apparent wind speed
AWA:
apparent wind direction
TWS:
true wind speed
TWA:
true wind direction
BS:
ship's speed
VMG:
'Velocity Made Good', that proportion of the sailing speed which is parallel with the
true wind.
1
VMG
AWA
BS
VMG = BS x cos (TWA)
2
VMG
BS
AWA
AWS
TWS
Wind speed/ wind direction indicator WSD834
AWS
TWS
TWA
WSD834M051
TWA
ENGLISH
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