Yacht heel (inclinometer) shows an indicative heel angle to port or starboard and fore–aft trim from the phone accelerometer. Access: Help → Safety at sea → Yacht heel.
Phone placement
- Lay the phone flat on deck or the nav table, screen facing up
- Point the top edge (speaker) toward the bow
- Do not hold the phone in your hand — you are measuring yacht heel, not hand movement
Display
- Semicircular inclinometer scaled 0–45° each side (PORT / STBD)
- Needle shows current heel and side (port or starboard)
- Colour zones: green 0–10°, amber 10–20°, orange 20–35°, red above 35°
- Numeric heel (signed) and trim in degrees
- Status: UPRIGHT or HEEL X° — side
Calibration: The “Zero (calibrate in calm water)” button sets the current reading as 0° — use when the yacht is upright in calm water before sailing upwind.
Audio alarm
- Above about 35° heel the app plays an audio alarm
- Alarm stops automatically when heel drops below the threshold
- Auxiliary signal only — not a stability assessment