My father has slight dementia. I want him to have an apple watch but pair it to my phone. Will all the features work if we aren't in the same place and can I use use "find my watch" from my phone to locate him if he wanders off and gets lost?
You can set up an Watch for a family member who does not use an iPhone.
Set up an Apple Watch for a family member -
https://support.apple.com/en-us/HT211768
M1 Mac mini, macOS 12.0.1; Watch, series 5 GPS/cellular, watchOS 8.1; iPad Pro 2nd Gen, iPadOS 15.1; iPad Air 2, iPadOS 15.1; iPhone 12 Pro, iOS 15.1; TV 4th Gen, tvOS 15.1; HomePods, audioOS 15.1 and Airport Express w/ Airplay 2
You can set up an Watch for a family member who does not use an iPhone.
Set up an Apple Watch for a family member -
https://support.apple.com/en-us/HT211768
M1 Mac mini, macOS 12.0.1; Watch, series 5 GPS/cellular, watchOS 8.1; iPad Pro 2nd Gen, iPadOS 15.1; iPad Air 2, iPadOS 15.1; iPhone 12 Pro, iOS 15.1; TV 4th Gen, tvOS 15.1; HomePods, audioOS 15.1 and Airport Express w/ Airplay 2
Apple watch
