It was the successor to Link's previous submersible, Deep Diver, which had been determined to be unsafe for use at great depths or in extremely cold temperatures.

[4] The aft compartment was originally designed for lockout diving, allowing two divers to be compressed to the ambient pressure of the ocean and leave the submersible to work underwater.

[2][3] In 1973, during a seemingly routine dive off Key West, the Johnson Sea Link was trapped for over 24 hours in the wreckage of the destroyer USS Fred T. Berry, which had been sunk to create an artificial reef.

[5][6][7][8][9] Over the next two years, Edwin Link designed an unmanned Cabled Observation and Rescue Device (CORD) that could free a trapped submersible.

One of the submersibles discovered the solid rocket booster with the faulty seal that had caused the shuttle to explode.