- Absolute Altimeter shows your current altitude above sea level. This is calculated from the local pressure (sourced from the device) and the local sea pressure / temperature.
- Local sea-level pressure and temperature are automatically downloaded for current location. Alternatively, they can be set manually if desired.
- Pressure, temperature and height units can be changed on either Watch or iPhone, with changes automatically transferred to other device.
- Apple Watch will derive local pressure from the iPhone when connected for a more accurate reading. However, it can also obtain its own local pressure, providing a slightly less accurate reading (still within a few ft).