In assessing the human problems which may occur in the development of a traffic system in an offshore area, some lessons may be learnt from the work which has been done on the similar problems arising in port approaches. There are several fundamental differences between the port and offshore problems such as the direction and density of traffic flow, the parochial as opposed to the international legislation and the difficulties that attend the positive identification of passing traffic. These considerations mean that it must not be supposed that the solutions which have been discovered in the port approaches may be simply transferred to the offshore case, but the similarity of aims in the two systems make a comparative study worthwhile. Basically, each authority must first legislate to allow control and guidance of the traffic. From this right to control must stem the obligation to organize the traffic into a scheduled stream, but this regulated stream will only reduce the risk of conflict if the schedule can be maintained by surveillance, communication and the cooperation of the mariner.