Support

• How do I hold it?

  Like a real hand bearing compass: hold your phone up at eye level, aim at your target (lighthouse, buoy, peak, vessel), and read the bearing off the vertical card in the center of the screen. The card stays level — you're just changing your viewing angle.

• Can I use it lying flat?

  Yes. Lay your phone flat with the screen facing up, and you'll see the compass rose from above — the usual circular compass view. The card remains level; you're seeing it from a different angle.

• What's the reciprocal?

  The bearing in the opposite direction, 180° away. In navigation, it's the back bearing from your target to you. HandBearing always shows it beneath the main reading, just as a real instrument does.

• Why do I need to calibrate it?

  The phone's magnetic sensor can be affected by metal nearby — your ship's structure, electronics, magnets in some cases, stainless steel fixtures. Move the phone in a figure-8 pattern, and the app will recalibrate and show you the accuracy. If accuracy stays poor, check for metal and magnetic sources around you.

• What's the Check against a landmark mode?

  A way to verify your readings. Pick a landmark (lighthouse, mountain peak, radio tower) whose position you know exactly, measure it in the app, then compare your reading to the true bearing from charts or a GPS receiver. If it matches, your compass is trustworthy in that location.

• Does it need location?

  Not to work. The compass is pure magnetic and inertial — no location required. You can save the location with each bearing if you want (disabled by default). Turn it on in Settings, and the app will ask for location permission.

• Is this an official marine compass?

  No. This app is an instrument aid, not a legal replacement for a vessel's required navigation equipment. Use it with proper charts, official information and your vessel's own instruments. The phone's magnetic sensor can drift and be affected by interference.

• What does night mode do?

  Switches the display to deep red illumination, which preserves your night vision. Just like a real hand bearing compass lamp used for night watch. Turn it on in the main screen.