The Ghost of the Sea was a man who was one of the underwater races who saved Commander Shore's life, and was also responsible for the accident that crippled him.
The Ghost destroyed a cobalt mining platform for unknown reasons, and was pursued by Sam Shore, who was then a Captain in the World Security Patrol. He ambushed Shore and crippled Shore's craft, but not before Shore rammed his sub and sunk it as well. The Ghost ended up rescuing the Commander and left him off the shore of Ecuador, where he was taken to a hospital.
Five years later, the cobalt mining rig was rebuilt, and the Ghost again attacked. This time, however, Stingray was present and gave chase. The Ghost attempted to ambush them again in the same way he had before, but the crew saw through his ruse and badly damaged his craft. He fled into a cave where Stingray could not follow, and then set the craft to explode when Troy and Marina came into the cave after him after fleeing the area.
While attempting to flee, he was trapped by a giant crawling clam, and could not free himself. Risking great personal injury and entrapment himself, Troy managed to free him. Grateful to the Terraneans for sparing his life, the Ghost returned in a different craft, signalling his thanks and peaceful intentions, as well as a desire to open peaceful relations.