The charts carry no scale of latitude and longitude, for they are based on direction and distance sailed on an earth assumed to be flat over the area covered.
Itshati ayithwali sikeyile somphakamo sobude, ngokuba zisekelwe kwindlela nomgama wokuhamba ngenqanawa emhlabeni cingela ukuthi tyaba phezu kwendawo egqunyiweyo.