Estimated position (EP)

An estimated position, marked EP and shown by a dot inside a square, is a dead-reckoning position corrected for the estimated set and drift of current and for leeway. Where a DR position carries forward only the course steered and distance run by log, the EP adds the navigator’s best estimate of the water’s movement and the wind’s push. The construction lays off the DR run, then applies the current vector (set and rate) and the leeway angle; the resulting point is the EP. It is used to predict a landfall, plan the next course to steer, and assess clearance when no fix is available. The EP is an estimate, not a fix, and its uncertainty grows with time.