PC15 was a diver lockout submersible launched in 1973 and owned by Vickers Oceanics, where it was known as L1.
In 1994, Patrick, Charlie and myself were contracted by Hoffmann Yacht Sales to manage the design and construction of a small 5-man submersible. The vehicle was to be part of a refit in Ft Lauderdale of the yacht Mystere owned by a Ukrainian oil millionaire and the starting point was the drastic conversion of this old Perry submersible, having once been a prototype submarine rescue unit with the UK navy.
The original PC15 was a long, drawn-out affair with a command module, a diver lockout chamber, a high-pressure breathing gas sphere the full diameter of the vehicle, various spool pieces and a main motor ‘cone' in the tail. Power was from external battery pods. Each section was fitted with flanges to enable it to be stripped into sections.
XPC15 required just the command module which had the conning tower. In place of the steel bow hemi and aft flange we fitted front and rear 150° spherical sector windows which were greater than the full hull diameter. The batteries were all internal and new soft tanks and new external structures were designed and built. Miraculously we maintained the ABS certification, which it retains to this day.
On Mystere the sub saw little actual use and was sold 4 years later to a tourist submarine operator in Milford Sound, New Zealand. The extra power demands from regular trips with 4 passengers down to 285m required a return to battery pods. We re-convened once again in Ft Lauderdale and re-designed the under-tray to incorporate re-furbished battery pods from the original vehicle. The vehicle was renamed Antipodes.
The commercial profile of the site in New Zealand was found to be not suited to an operation like this so the vehicle eventually returned to Pete Hoffman in Fort Lauderdale. After a refit period it was later sold on to Ocean Gate based in Seattle where it is gainfully employed in ocean science.