Two main problems prevented its immediate application: the impossibility of determining the longitude at sea with adequate accuracy and the fact that magnetic directions, instead of geographical directions, were used in navigation.
Issin muškila tan igdalan assăxdim net daɣ armud: Iban tudăbat n musnat n tašijrit daɣ eɣašar s iqqud d awa fal tisdăg magnetic a axdămnen daɣ asikil fal amăn uhun tisdăg tin jografia