1. Hovercraft Development Ltd was established in 1959 by the National Research Development Corporation (NRDC) to develop and exploit the early hovercraft patents. HDL had a facility at Hythe on Southampton Water where the HD-1 and HD-2 development craft were developed.

The HD-1 was of mainly wooden construction and was built by ship builders J. Samuel White of Cowes, Isle of Wight - the craft was described as the first non-amphibious craft with air curtains at both the front and rear (or bow and stern for the nautically minded!). Built as a full scaled test bed for skirts and control.

The HD-2 was produced as a full sized test vehicle to research hovercraft controls.

In October 1967, the development and research aspects of HDL were transferred to the National Physical Laboratory to form the NPL Hovercraft Group. HDL continued with the licensing of the hovercraft patents. The Hythe site continued until the mid 1970'

Craft: HD- 1, HD-2, HU - 4 , Hover bed, Tracked Hover,