A.Running fix B.Fix C.Dead-reckoning position D.Estimated position
A.Current can be determined by measuring the direction and distance between simultaneous EP and DR positions B.The drift of the current should be averaged out on a one hour basis C.After the current is determined,it should not be used for further plotting because it is an unknown variable D.The distance between a simultaneous DR position and fix is equal to the drift of the current
A.Dead reckoning position B.Leeway position C.Estimated position D.Set position