This prompted him to not only purchase a Mk15.5 but to replace its analogue electronics with the digital ones of the Juergensen Marine Hammerhead, resulting in a specially modified POD designed to handle extreme pressures.

For extended dives in caves shallower than 150 m,[citation needed] Shaw used his Cis-Lunar since he believed it had superior redundancy capabilities, but could not cope with extreme depths.

On 28 October 2004, Shaw descended to a depth of 270m at Bushman's Hole, South Africa, breaking the following records: He used a Mk15.5 with Juergensen Marine Hammerhead electronics and the following gas mixtures: trimix 4/80, 10/70, 15/55, 17/40, 26/25, air, nitrox50, 100% oxygen.

[2] On this dive, Shaw discovered the body of Deon Dreyer, a South African diver who had died in Bushman's Hole ten years previously.

[3] Shaw recorded his dive with an underwater camera, which allowed researchers to determine that he suffered from respiratory issues due to the high pressure.

Normally he would have wrapped the wire behind his neck, but he was unable to do so; the lines from the body bag appear to have become entangled with the light head, and the physical effort of trying to free himself led to his death.