Spray, a sleeve or a crew member leaning on the mount can change the screen without anyone meaning to. The lock stops that. While it is on, the chart and fields keep updating at full contrast, but nothing you touch changes them, except MOB.
Lock it
Tap Lock in the status strip. It turns to Locked, and the bottom bar is replaced by Hold to unlock with a ring beside it.
Unlock it
Press and hold Hold to unlock. The ring fills over two seconds, and the screen unlocks when it is full. Let go early and it stays locked.
With VoiceOver, the Unlock control unlocks straight away when you activate it.
MOB through the lock
MOB stays live while the screen is locked. A tap marks the position and starts the return display, exactly as when unlocked. Nothing else on the screen responds.
Lock automatically
Lock the screen face down or covered (Settings › Cockpit) is on to start with. With it on, the screen locks:
- when you lay the phone face down for about a second, with the notice Locked: face down;
- when the proximity sensor is covered, for example in a pocket, with the notice Locked: covered.
It always takes the two-second hold to unlock, however the lock came on. Turn the setting off if you would rather lock only by hand.