 In particular, the firm held an intense interest in developing advanced watercraft, such as its commissioning of a two-year study into the potential production of nuclear submarines for freight delivery purposes and the development of an advanced amphibious beach survey vessel, known as WALRUS.Also during this time, British engineer and inventor Christopher Cockerell had been exploring his own concepts on how to produce more efficient fast-moving watercraft, involving multiple technologies such as inflatable air cushions, pump-jets and centrifugal fans; these would effectively emerge as a single new form of amphibious vehicle, later known as the hovercraft.Having tested and found substance to his theories during the early 1950s, Cockerell proceeded to approach various aircraft companies and shipbuilders, but had difficulty gaining their backing, in part due to a lack of understanding of the technologies involved.