What eight year litigation involved the United States Supreme Court and a scuba diver?

In the 1980s, diver Mel Fisher continued to search for the Spanish Plate fleets and sunken treasure.  In 1985 on July 20th, the Atocha wreck along with her cargo of emeralds, gold and silver was found.  Upon hearing of the discovery by Mel Fisher, the United States Government attempted to claim the wreck causing the State of Florida to step in and seize many items.  After eight long years of litigation, Fisher was returned his belongings after a ruling in his favor by the United States Supreme Court.