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B&G H2000 Pilot *DISCONTINUED* User Manual

Page 70

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h2000 User Manual

70

HB-0845-06

Tacking Performance has a CALBRATE option that allows
you to choose a type of polar table that equates to your type
of yacht. In the next Paragraph, Target Boat Speed, we
discuss polar tables in general and the implications of this
choice.

2.9.43 Target Boat Speed

Menu heading: PERFORM
Function text: TARG SPD
Update

rate:

1Hz

Units: Knots

Notes

1.

At Target True Wind Angle.

2.

Requires a Performance Processor.

This is the boat speed at which the optimum VMG will be
achieved, and can be measured from the polar table or
obtained by careful analysis of both VMG and boat speed
while you are sailing.

The Polar Table describes the performance of the boat in all
conditions of True Wind Speed and Angle. The Boat Speed
is plotted radially against the True Wind Angle for each
True Wind Speed in turn. The result is a diagram as shown
in Figure 4 - Polar Performance Curve, which shows the
boat speed plotted for just one value of true wind speed.

Polar tables can be derived either by theoretical predictions,
the IMS certificate for instance, or by analysing the boat's
actual performance. You may well use one of these
techniques to obtain your polar table, however, if you do
not, then the h2000 has one polar table already stored in its
memory. A copy of this polar table is shown in Table 3 on
page 87.

The polar table is located within the h2000 system under the
following:

PERFORM

TACKING, CALBRATE

CAL VAL1 (TAB TYPE)