Best magnetometer for a compass

hi, I have tried to use a BNO055 to us as artificial horizon together with a directional compass. Unfortunately both, the artificial horizon, as well as the compass heading drift off, unusable for navigation, after a short while.
Also I can`t calibrate the BNO055 every time, by moving it as recomended through all 3 axis, since it is rigidly installed.
Is there another magnetometer sensor, that would be better suitable for a compass?
truely,
John

Do you want just a compass, or an artificial horizon too?

For a compass, I recommend the LSM303D, using Pololu's tilt compensated compass code.

However it is absolutely essential that you calibrate any magnetometer properly, and if this is to be fixed in place, that can present a real problem.

Follow this post and the links therein to calibrate the compass: https://forum.pololu.com/t/correcting-the-balboa-magnetometer/14315