Draft (T)

Draft, T, is the vertical distance from the waterline down to the lowest point of the hull, the molded baseline at the keel, measured at a given longitudinal station. It sets the immersed depth and, with LWL and beam, the displaced volume and the block coefficient (CB = displaced volume over L times B times T). Mean draft is the average of forward and after drafts; the difference between them is the trim. Draft is read from the draft marks and governs underkeel clearance, channel and berth access, and the load-line limit on how deep a ship may float. Molded draft is measured to the baseline; extreme draft adds the keel and any projection below it.