Tom Swift and His Undersea Search by Victor Appleton
Times have changed. The Great War is over and money is getting hard to come by. Mr. Damon shows up with a new friend, who promises wealth from the bottom of the sea. Tom reluctantly agrees to join the search for the sunken steamship SS Pandora and a million dollars in gold coin.Like the Greek legend, the strong box on the Pandora contains much more and less than the treasure seekers expected.