Owner's manual

HB-0845-06 79
2.9.54 VMG
Menu heading: SPEED
Function text: VMG
Update rate: 1Hz
Units: Knots
Note
1. Upwind/downwind Referenced.
As a measure of performance VMG has both advantages
and disadvantages. It is calculated from the true wind angle
and the boat speed.
True Wind
Direction
VMG
5.54
Knots
Boat Speed
6.4 Knots
True Wind
Angle = 150
VMG KT
BOAT SPD KT
Down Wind
VMG
4.44
Knots
Boat Speed
5.8 Knots
True Wind
Angle = 40
True Wind
Direction
Up Wind
VMG KT
BOAT SPD KT
Figure 7 - Calculation of VMG