2020-08-02, 07:07 PM
You need to calibrate on the boat because magnetic objects on the boat itself interfere with the field. The field in a house is also very distorted as most houses have steel in the walls, and small movements in position will greatly affect the field, so if you calibrate in a house be careful to rotate the sensors but not move them to different locations in the house.. You will have to recalibrate anyway on the boat to fix the bias.