When used at sea, satellite compasses are capable of determining the course of a sailing vessel with high accuracy. It is difficult to verify the accuracy declared by the device manufacturer under such conditions, as it is difficult to define a reliable reference. This study analyses the accuracy of the satellite compass in an urban setting, with the satellite signal being obscured to various extents. It is an important point in the study to refer the measurement results to a reference route, which is the axis of a tramway track, determined by the precise GNSS RTK method. The measurement data were processed in the original software developed by the authors. The results demonstrate a high 2D positioning accuracy with low height determination accuracy. The course determination errors exceed the limit values declared by the manufacturer. However, specific measurement conditions must be taken into account, which differ considerably from the typical applications of a satellite compass.