I need to understand something. I assume the bracelet communicates with the smartphone. If the smartphone is in a villa or on a yacht. How far can the bracelet communicate with the smartphone ? What happens if the smartphone is turned off. Can the bracelet determine where you are if you are in the water with a scuba tank? I understand that a resort allows folks to move about the entire resort. Thinking of Oil Nut Bay maybe a mile or so. How does that work?

How does the bracelet work in a villa. I have about 1/2 mile of land can I move about on the land? Or in the water?
Thanks