The easiest method of checking the deviation is to take a compass bearing of two fixed objects in transit, then comparing this bearing with the True Bearing measured from the chart.
Eyona ndlela ilula yokukhangela ukuguqu-guquka kukuthatha isiphathi salatha mbombo yezinto ezimbini kwisithuthi, wandule ukuthelekisa esisiphathi nesiphathi esiyinyani elinganiselwe etshatini.