The watchOS2 update brings forth a new security feature called Activation Lock, which is meant to prevent against the unauthorized use of stolen or misplaced Apple Watch. Activation Lock is part of iCloud's Find My iPhone service and until now it was only available for the iPad, iPhone, and iPod Touch.
This tutorial will teach you how to enable the Activation Lock feature of your Apple Watch.
Activation lock will be automatically enabled on your Apple Watch as soon as you activate Find My iPhone on the companion iPhone or iPad. But in order to take advantage of this feature, you'll need to unpair the Apple Watch from your iOS device and pair it again.
The first step is to unpair your Apple Watch: Open the Watch app on the companion iPhone or iPad and go to My Watch > Apple Watch > Unpair Apple Watch.
Next, you'll need to set up Find My iPhone on your iPhone or iPad (Apple ID required): Go to Settings > iCloud and sign in with your Apple ID. Toggle Find My iPhone on and follow the onscreen instructions.
Once that Find My iPhone is enabled, you can proceed to the pairing of the Apple Watch. For more information, please read our article How To Pair Your Apple Watch.
Moving forward, Activation Lock will be enabled on your Apple Watch. You can check the status of the service on your device by clicking activation lock and signing in with your Apple ID.
How To Remotely Lock an Apple Watch
You can lock a lost or misplaced Apple Watch from the Apple Watch app installed on your iPhone or by signing in to iCloud with a web browser.
From the Apple Watch App
On the companion iPhone, open the Apple Watch app and go to My Watch > Apple Watch. Tap on Mark as Missing.
From a Web Browser
Sign in to iCloud and go to the Find My iPhone tab. Select your Apple Watch from the list of devices and then place it in Lost Mode.
What Happens when a Device is Marked as Lost
Activation Lock will help to prevent against an unauthorized use of the Apple Watch (turn off Apple Pay cards, disable access to your personal content, and prevent pairing with a new device).
Furthermore, devices marked as Missing/Lost can't be erased or activated without the correct Apple ID.
N.B. You won't be able to use Find My iPhone to locate your Apple Watch on a map. This feature is exclusive to the iPhone, iPad, and iPod Touch.