The Apple Watch needs a qualifying iPhone to work. But, let's say if you are out of bluetooth range of your phone, for example if you are swimming and obviously you can't bring your iPhone with you (unless you also bring it and put it inside a waterproof bag, but cumbersome), will the Watch still function as a timekeeping device only? Obviously you'll lose the notifications or be unable to use Apple Pay for example, but what are the other things you can still use without a bluetooth connection to your phone? Other similar scenarios might be you are flying and your phone is in airplane mode, but you'd still like to see what time it is or be able to use the countdown timer so you know how much time is left for the flight.