18.2.1 Fluxgate compasses are acceptable under
the Code, as an alternative to that required in 18.1, provided that
a suitable back-up power supply is available to power the compass
in the event of failure of the main electrical supply.
18.2.2 Where a Fluxgate compass incorporates a
capability to measure magnetic deviation by undertaking a calibration
routine, and where the deviation figures are recorded within the device,
a deviation card is not required.