⛵ Marine Compass
Magnetic Heading Reference · Always Verify with Dedicated Marine Equipment
⚠ Maritime Safety Notice: This tool shows magnetic heading from your phone's sensor. Magnetic variation, vessel interference (engine, electronics), and device limitations mean this is a reference tool only. Always use certified marine navigation equipment at sea.
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Tap Start to activate
↻ Figure-8 to calibrate
Marine Use Notes
- Magnetic variation: This reads magnetic north. Check local nautical charts for magnetic variation (declination) in your area to convert to true north.
- Deviation: Metal on your vessel — the engine block, steel fittings, electronics — creates its own magnetic field that interferes with phone compass readings.
- Calibration at sea: Perform figure-8 calibration with your phone away from the vessel's electrical components and metal structures.
- GPS cross-check: When underway, compare your compass bearing with GPS course-over-ground (COG) as a sanity check.