“The object is small and the darkness total”: how do you rescue a missing submarine near the Titanic?

Where’s the Titan? At best, it floats on the surface, but has not yet been found. At worst, it has become entangled at a depth of four kilometers and suffered the same fate as the Titanic itself. How the hell do you rescue a submarine that is no bigger than a large van in a search area that is many times Belgium? Even NATO doesn’t have a submarine that can go that deep.

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