Marine archaeologists from the National Oceanic and Atmospheric Administration and the State of Florida are wrapping up a 10-day mission to document an unknown shipwreck -- possibly centuries old -- in shallow waters off Marathon in the Florida Keys. The team hopes to eventually identify the mysterious wreck and add a new chapter to maritime history. Archaeologists are mapping the ballast pile, exposed ship timbers and coral on the site—located about a mile-and-a-half south of Marathon in the Atlantic Ocean in only 18 feet of water. State underwater archaeologist for the division of historical resources, Dr. Roger Smith, says the ship is probably Spanish.

“But it represents an opportunity to look at how a colonial-period shipwreck has fared and how it's been incorporated into the environment in the Florida Keys. And you have a spectacular amount of coral growth on top of the shipwreck, which is on top of the original coral growth. And so we're looking at the integration of cultural and natural resources and how they exist together."

The team is taking small samples of wood from the remaining timbers and conducting some minor excavation. It will also survey the area seaward of the wreck to see if there are any more artifacts nearby. The expedition concludes today.