When a course line or bearing is drawn, the rulers are placed either against the correct compass reading on the rose printed on the chart and then moved one at a time to the required position, or by moving the index of the rulers to a longitude meridian and noting the correct reading against the same meridian on the outer edge.
Xa lemigca inxibelelanayo izotyiwe, ezi zilawuli zibekwe malunga nesalatha mbombo sokufunda kumzobo ozotywe kwitshati kwaye kususwe ubemnye ngexesha ukuya kwindawo efunwayo, okanye ngokususa izalathiso sesiphawuli ukuya.