Deep Diver was the name of a deep-sea scientific research submersible designed by Edwin Albert Link.
Its name was subsequently changed to Deep Diver and its ownership transferred to Link's company, Ocean Systems, Inc.[1][3] The submersible contained two compartments: a divers' compartment, developed from Link's earlier work with his Submersible Decompression Chamber (SDC), which allowed divers to be compressed to the ambient pressure of the ocean and leave the submersible to work underwater, and a pilots' compartment which remained at surface pressure, allowing the pilot and an observer to make dives without undergoing decompression.
[2][4][5]: 91–103 In September 1967, Deep Diver carried out a classified Ocean Systems mission on the Grand Banks south of Newfoundland.
A crew of four Ocean Systems personnel, including MacInnis, unsuccessfully attempted to recover the cable plow using the submersible.
The mission was called off due to rising winds, and Deep Diver was barely brought safely back aboard the Canadian Coast Guard vessel CCGS John Cabot.
[2][5]: 81–90 Later in 1968, after Deep Diver had been requisitioned by the United States Navy to help search for the lost submarine USS Scorpion, the Bureau of Ships determined that Deep Diver was unsafe for use at great depths or in extremely cold temperatures because of the substitution of the wrong kind of steel, which became brittle in cold water, in some parts of the sub.