B&G Hydra 2000, User Manual

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Hydra 2000 User Manual
Part 3 - Calibration
HB-0844-02
3-20
Wind Angle True Wind Speed
5 10 15 20 25 30
Upwind 2 4 3 2 1 1
Reaching 3 5 6 5 4 3
Downwind 0 0 0 0 0 0
Table 3.1 - Example of True Wind Angle Correction Table
The formatted table (Table 3.1) is carried in the Hydra 2000
memory and it is necessary to determine and enter the relevant
corrections for true wind direction. The correction is calculated
empirically and from which some general rules can be
determined.
Fig 3.6 - True Wind Direction Error
Fig 3.6 is a typical situation, sailing on a port tack, upwind, in a ten
knot wind, the true wind direction reads 210°. The vessel then
tacks to starboard and is maintained on a steady course. The true
wind direction now reads 200°. There is a 10° error tack to tack.
The true wind direction should read 205° on both tacks. To correct
the true wind angle so that the true wind direction reads 205° on
both tacks, 5° should be added to the true wind angle. As a
general rule it can be said: