The HSC100 should be accurate to +/- 3º through the full 360º. Any nearby ferrous items that cause a deflection/deviation in the local magnetic field around the HSC100 should be calibrated out by the calibration routine detailed in the manual and also shown here in an old video I made… It is important that the calibration is carried out in the calmest of conditions possible, with minimum tide and wind effects.  Read More →