The Henderson based family owned business Pozztech Engineering, have successfully completed the manufacture, non-destructive examination and function testing of what could be the deepest 3 person submersible decompression chambers ever manufactured, designed to dive in excess of 500 meters of seawater and weighing in at over 10T each with their 40mm thick shell. Considerable in-house engineering has enabled the PD 5500 class 1 vessel design materials (designed in the UK to European material standards) to be substituted for high-quality Australian made steel which has been incorporated into the manufacture of the submersible decompression chambers and exo-structure. The materials of manufacture range from normalized carbon steels with excellent weldability and improved notch toughness to marine grade stainless steels, duplex, and nickel bronze aluminum. The two units, which are a Lloyds Register class 1 pressure vessel, have undergone an extensive testing regime never previously performed on similar units with zero repairs and zero injuries during the 7-month manufacturing and testing process. Pozztech Engineering would like to extend sincere appreciation to the local vendors who supported the manufacture of these world-class units for the Australian manufacturing industry.