Safely Charging the Watch

The simple answer is that if the adaptor has a USB port which accepts the charging cable you can use it to charge your Apple Watch. The watch has a very low power demand, so any adaptor should have the muscle, and it doesn’t matter about a high rating on the label because that is only the maximum the charger can support. The watch controls the process and keeps the charging rate at a safe level. Even a car audio USB is ok, or a computer USB port will work provided the computer is powered up.

No.

Check your battery and charge your Apple Watch - Apple Support

Now I’ve seen which adaptor Phil linked... That 2.4A adaptor is exactly what lives in my travel kit to charge iPhone, iPad, Apple Watch, and a few other devices by swapping to a mini or micro USB cable. It has been used in hotels and ships all over the world, on any input voltage from 100v to 230v and never a problem.

You've had more than one tie-breaker and Phil gave you the official Apple link where it shows that the 12W charger is compatible with the Apple Watch. If you go with the 1.0A charger you will need to turn off your iPad and allow quite a bit of time to charge it. Take the 12W instead. Your devices will not allow themselves to be overcharged. And this time Carolyn is partially wrong, I've never used the adapter that came with my watches, I've always used a 12W. It is not best to use the one that came with it when you also need to charge your iPad.

No, she is incorrect, you can use the iPad power adapter.

No. You can use the 5 watt iPhone charger, or the 10 or 12 watt iPad adapters.

Both are supported with the watch.

See here for compatibility: Apple 12W USB Power Adapter - Apple

Best to use the charger that came with the Apple Watch.

Ditto, in my backpack and one in my electronics travel bag. Plus the one plugged into the wall for my charging stand in the bedroom.