Pro Altimeter for Watch 1.0.3

The Pro Altimeter for Watch is the latest application developed by Hunter Research, known for their esteemed outdoors app, Theodolite. This app leverages the advanced barometric pressure sensor present in the Apple Watch to accurately measure altitude. Although designed as a Watch app, it maintains the comprehensive features and precision found in its iPhone and iPad counterpart, offering a compact experience right on your wrist.

Pro Altimeter features a streamlined interface that enhances usability. It displays both barometric and GPS altitudes in large, legible numbers, with options for units in feet or meters, alongside real-time accuracy estimates derived from the hardware. Calibration and settings buttons are conveniently located at the bottom of the display. The app presents highly-readable color schemes, including luminescent green on black, white on black, and midnight red on black.

Calibration is essential for accurate altitude measurement based on barometric pressure. Pro Altimeter provides several calibration methods to accommodate user preferences:

1. GPS Altitude: This method aligns the local barometric pressure with GPS-measured altitude, suitable when the device has clear visibility to the sky with a trustworthy GPS fix.
2. Manual Entry of Altitude: Users can input known altitude from landmarks, elevation benchmarks, or topographical maps by entering values in feet or meters.
3. Manual Entry of Pressure: For those with access to a weather station or METAR report, local barometric pressure can be entered using units such as inches Hg, kPa, or mb to determine altitude.
4. Local Airport Data: With a simple tap, Pro Altimeter identifies the five nearest airports within 100 miles (160 km) and retrieves METAR data for calibration purposes.

Once calibrated, Pro Altimeter diligently tracks the time elapsed since the last calibration. Given that weather conditions and local barometric pressure fluctuate, users receive a timely warning after six hours through a flashing "CAL" button. Frequent calibration is recommended—such as during hikes at trail markers or elevation benchmarks—but it is essential to recalibrate at least every six hours or whenever significant weather changes occur.

This application is compatible with all Apple Watch models operating on watchOS 8.3 or later.