Unlike the iPhone, the Apple Watch doesn't yet feature Activation Lock.
A theft deterrent system that requires your iCloud password to be disabled, Apple added Activation Lock to iOS in 2013 The Apple Watch, which runs a variant of iOS called Watch OS, doesn't yet secure the device beyond the default passcode/password intercept on the clock face. This was first noticed by @enMTW immediately following the Watch launch in April, but gained wider attention today following a story on iDownloadblog. So, what does it all mean?
No regular watch has a passcode or password, much less online theft-deterrent system, including those sold by Seiko, Timex, Omega, or Rolex. Because the Apple Watch stores some amount of personal data on it, it however, it does have value and risk beyond a regular watch. To mitigate that, you can set the Apple Watch passcode/password system to erase all data after 10 failed attempts.
The interesting part here is that the Apple Watch has all the elements in place to offer Activation Lock, and so the potential to offer even better security. My strong suspicion is that they simply haven't implemented the Watch-specific process for it all just yet. The Watch is unique in several ways — it's brand new, it has more limited input options, and it requires a paired iPhone to go online.
On an iPhone it's relatively painless to enter even a strong, unique, pseudorandom iCloud password on the rare occasions you need to, and to do it directly on-device and online. For the Watch, this process will need to be carefully reconsidered.
Given the emphasis Apple has placed on security in recent years, and how much the company has improved the iPhone as of late, I'd also strongly suspect it won't be too long before we see just that — Activation Lock on the Apple Watch.
In the meantime, there's no reason to panic. Secure your Apple Watch with a passcode or password and set it to erase after 10 failed attempts. And then treat it as you would any high profile, valuable piece of electronics or jewelry.
The real difference is, unlike a regular watch, the Apple Watch can and will be improved every time Apple improves Watch OS.