On the eastern edge of Gravesend Bay, just at the mouth of the Coney Island Creek in Brooklyn, New York, there lies a makeshift graveyard for old barges, scows, pleasure boats and other decrepit vessels. Occasionally, at low tide, an unusual shape can be seen protruding from the water near the wrecks. It is that of a submarine’s conning tower. The sub, swept by storms and high tides, has been popping up at various sites in the area for more…