Airplane mode on Apple Watch, by default, mirrors the setting on your iPhone. When you disable Airplane mode on your iPhone, it can not be mirrored to Apple Watch, because the radios on the watch are turned off. You need to disable Airplane mode on Apple Watch manually by using the interface on the Apple Watch.
You can disable the automatic mirroring of Airplane mode the following ways:
iPhone
- Go to the "Apple Watch" app
- "My Watch"
- "General"
- "Airplane Mode"
- Make sure the "Mirror iPhone" switch is turned off.
Apple Watch -
- Go to the "Settings" app
- "Airplane Mode".
- Make sure the "Airplane Mode" switch is turned off.
I imagine the WATCH will keep as much data as its onboard storage will allow, which is several gigabytes. So, caching Health data really shouldn’t be an issue for most intents and purposes.
Since the title of the question is about the disadvantages of Airplane mode, know that placing your WATCH in airplane mode will preclude you from connecting to the Internet. Therefore, any feature that requires an active Internet connection will not work. Siri comes to mind.
Finally, since the Bluetooth antenna is also disabled, you will be unable to connect a set of Bluetooth headphones, or an external heart rate monitor. Any app that requires an iPhone connection will not work either, meaning all watchOS 1 apps, as well as many, if not most, watchOS 2 apps. GPS via your iPhone will also cease to function.
Enabling Airplane mode thus disables most of the features of your WATCH. On the other hand, there aren’t too many advantages to enabling it. You might see some gains in battery life, though most of that will come from not being able to use your WATCH for a whole lot of things. But if you weren’t using your WATCH a lot to begin with (outside of activity tracking), then battery life is more than adequate to last you an entire day.
Even if you are on a marathon hiking trip, you will defeat much of the purpose of tracking that workout anyway, since the lack of GPS will result in less accurate distance measurements. In that situation, it would be preferable to turn on Power Saving Mode
under Apple Watch → Workout.
Best Answer
On your iPhone in the Apple Watch app, scroll down to Passcode. Create a Passcode then enable “Turn Passcode On”. Scroll down and enable Wrist Detection. With that enabled, anytime your Apple Watch is not on your wrist, passcode needs to be entered to access any of the watch functions.
However, if they are hell-bent on accessing your watch information, while you are wearing the watch… nothing is stopping them from cutting your arm off and using your watch while it’s still on your wrist LOL