AUTOHELM ST80 - Compass Offset Page

118 ST80 Masterview Operation and Setup
D2219-1
BOAT SPEED = 2 KNOTS
3. Linearisation is now complete
Compass Offset Page
Once the compass has been linearised, the displayed heading must be
matched to a known transit bearing.
D2222-1
The main offset page displays your current heading and the heading
offset value.