1, the geological compass must not be placed underground.
2, the accuracy of holding is always worse than putting it down. The error between horizontal and final sitting posture is less than 0.5 degrees, which is difficult to maintain.
Generally speaking, geologists will put a layer of fine sand on the table to adjust the level. Clothes should also play this role, but the level is hard to estimate. You should be able to put the compass in your hand.