goonbag My Garmin GPS headunit (aka Bike Computer) requires my phone. I tell it up to 5 contacts and when it detects a potential fall, it informs you “I am about to send a message to your contacts with your current location. Cancel this within 30 seconds if you don’t want to do this”. I’ve had it false positive once and I thought it was pretty great. Had plenty of time to come to a safe stop and tell my GPS that I’m OK and not to text my wife and brother.
Apple Watches are sold with and without cell radios. If you have a non-cellular watch, you’d need your phone. It’s my understanding it works in a similar fashion with text messages. I don’t have a watch like this so I can’t speak much more about the features that are marketed as location-sensitive safety features.