The past 10 years have seen an explosion in the use of high speed marine craft. This explosion has been in most sectors of operation, leisure, passenger carrying and military, and is now poised to expand into the cargo carrying sector. The sizes of the new generation of fast craft can range from small 60 knot, 7 metre leisure craft up to fast ferries which are 140 metres long with speeds of 40 knots. Future developments encompass 40 knot large cargo ships, 100 knot passenger and cargo vessels and very high speed military craft. Added to this galaxy of high speed concepts is the 200 knot wing-in-ground (WIG) craft, which, because it flies close to the sea surface, will interact with other marine traffic.