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B&G H2000 Pilot *DISCONTINUED* User Manual

Page 69

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HB-0845-06

69

The h2000 calculates the optimum VMG from the polar
table for the wind speed and then compares this to the VMG
actually being achieved, displaying the result as the tacking
performance percentage. The same problems of time lag
exist here as they do with VMG, this is discussed in the
section on VMG.

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9 Kts

Boat Speed

Target Boat

Speed Downwind

Target Boat

Speed Upwind

Optimum True Wind

Angle Upwind

Optimum True Wind

Angle Downwind

Maximum VMG

Upwind

Maximum VMG

Downwind

True Wind Angle

Port Tack

True Wind Angle

Starboard Tack

Figure 4 - Polar Performance Curve

The advantage of tacking performance over VMG is that it
takes into account changes in windspeed. You should also
be aware of the potential inaccuracies caused by your polar
table being incorrect.