Furuno 520 - Manual (Page 49)

4. MENU OPERATION
4-11
Locking the control unit
The LOCK feature renders the following commands inoperative from the control unit at
which the LOCK feature has been actuated.
• Menu operation
• Changing the steering mode
• Course setting
• Waypoint switching
1. Rotate the course control knob to select “LOCK” from the SYSTEM SETUP menu.
2. Press the course control knob to show the lock options window.
LOCK
UNLOCK
Lock options window
3. Rotate the course control knob to select “LOCK” or “UNLOCK” as appropriate.
4. Press the course control knob.
To unlock, press the [STBD] (►) key while holding the [TURN/MENU] key down.