Entry Date:
December 1, 2001

Wake Wash of High-Speed Vessels in Restricted Waters: Should There be a Speed Limit

The advent of modern vessels designed to cruise at high speeds in coastal waters has brought the importance of their wake wash to the forefront of the field of marine hydrodynamics.

In several accidents, “killer waves” generated by high-speed ferries have been reported. Hence, the concern of the public, regulatory authorities and ship designers has been raised regarding the (nonlinear) surfacewave physics governing wake-wash generation and the dependence of wave amplitude on vessel speed and hull shape. The question often asked is “Should there be a speed limit, and if so, what should it be?” This new research activity has concentrated on the development of mathematical and numerical models for the three-dimensional nonlinear solitons generated by high-speed vessels. Examples of two such waves generated by a high-speed vessel advancing at the critical and super-critical speeds in shallow water are illustrated. One important observation of this research is that the shape of the crests of the upstream solitons is almost exactly a parabola. Future research will consider the sensitivity of the amplitude and period of such shallow-water waves to the vessel speed and hull shape.