Device for preventing error in a compass

A compass for preventing error or misreading fastened to a sloping plane of a boat, the compass comprising a spherical casing, a pendulum mounted for limited pivoting movement in a first plane inside said casing, a sealed compass disk having a mounting point rotatably and pivotally mounted on said pendulum, a steering line on said pendulum, said sealed disk being intended to be read at an angle of 0.degree. to about 45.degree. relative to a horizontal plane, a cradle pivotably mounted inside and to the spherical casing for movement relative the spherical casing in a second plane substantially at right angles to said first plane, said pendulum being mounted in said cradle for pivoting movement thereon in said first plane, the steering line of the pendulum and said mounting point for said disk on the pendulum being continuously maintained by the action of gravity in the same vertical plane relative the fore-and-aft line of the boat independent of the heeling of the boat.