UKC

Under-keel clearance (UKC) is the vertical gap between the deepest point of a ship’s hull and the seabed. Static UKC is the simple difference between charted depth plus tide and the ship’s draft; dynamic UKC subtracts allowances for squat, heel, wave-induced heave, pitch and roll, and survey and tide uncertainty. Deepwater ports run dynamic UKC management systems (DUKC) to widen tidal windows safely for deep-draft ships. Too little UKC risks grounding; too much margin sacrifices cargo intake or sailing windows.