During the year 2000, an unusual meeting took place with a next door neighbor (Francis 'Frank' Smith) of the then HMAS "Stirling" Naval Base commander. He was an Aircraft Maintenance Engineer (originally trained at Government Aircraft Factories Fisherman's bend) who had been aware of the fluid dynamics issues of the Collins class for some time, purely by interest and observation on television. After a lengthy discussion, he was invited to discuss and demonstrate where possible, his observations at the "Stirling" Naval Base with Navy and DSTO staff who were there at that time as part of an investigative group. He showed on a white board, the aerofoil issue with the Dorsal – Sail conning tower structure showing that the aspect ratio (span (height) to chord (width)) was too short and that severe turbulence / cavitation would be generated by such a design. This was demonstrated again on the white board using aircraft aerofoil wing shapes as a basis for the discussion. That the turbulence / cavitation generated would, by natural rearward flow, move down the rear upper surface deck of the hull and be drawn into the propeller. He was also able to demonstrate that the design of the bow section would not pass a flow test for generated turbulence / cavitation, with the change in shape from circular bow section to long hull, being ill-conceived. He made several recommendations during the lecture that would be cost-effective and possible. 1) To lengthen and taper the dorsal fin and create a more streamlined integration of the dorsal to flat upper Hull deck section. and 2) To 'fill in' the hollow section of hull aft of the bow curvature. Both these could be achieved with Carbon Fibre or Fibreglass covers as no load bearing strength would be required. Subsequent studies by the Defence Science and Technology Organisation showed that the submarine's hull shape, particularly the redesigned sonar dome, the fin, and the rear of the submarine, focused the displaced water into two turbulent streams; when the seven propeller blades hit these streams, the propeller's vibration was increased, causing cavitation. These problems were fixed by modifying the casing of the submarine with fiberglass fairings.