It follows that if ships cannot shut their doors at a particular berth, because of the design of that berth, then alterations should be made to the berth. Alterations have been made to some berths, but it is considered by the Court that all berths on U.K. routes should be altered so that ships with clam shell doors or normal stern doors are able to shut their doors before leaving the berth. It is desirable that each berth should then carry an approval certificate specifically listing the ships which can operate from it, and can shut their bow and stern doors without moving from the berth. Parliament may wish to consider whether it should be an offence for a ferry to leave a berth before its bow and stern doors are closed.