System information

Alarm system | 77
Boat speed calibration
The hull shape or the location of the speed sensor may
cause incorrect speed readings, and it may be required to
calibrate the input to ensure that correct speed and log
values are displayed.
Calibrate by Speed Over Ground
With a GPS connected to the system, the speed through
water (SPD) can be calibrated equal to Speed Over
Ground. This adjustment should be made in calm sea
with as little wind or tidal current as possible.
1 Bring the boat up to a constant cruising speed
(above 5 knots)
2 Select Calibrate w/SOG and press the MENU key
3 Press the MENU key again to confirm and execute
the calibration
4 The SPD Correction factor will now be changed to
equal the SOG and SPD values
Manually adjust the speed value
If you experience an incorrect speed reading, this can be
manually re-adjusted by running the boat at constant
speed over a known distance in both directions and
average the speed reading. This reduces the effect of
wind and tidal current.
Then adjust the SPD Correction factor to get the correct
speed reading.
Range Change per step Default
0.50 – 1.50 0.01 1.00