An insulating material suitable for use in a diver's garment or garment-like apparatus. The insulating material comprises a multiplicity of layers of a flexible, stretchable material. These layers include a central core consisting of a gas permeable, preferably multicomponent, layer of a material that...http://www.google.co.uk/patents/US4274158?utm_source=gb-gplus-sharePatent US4274158 - Evacuated diving suit insulation
