In the turquoise blue waters of the Florida Keys, a new attraction is drawing scuba divers from around the world: The USNS General Hoyt S. Vandenberg. Laid to rest in the Florida Keys National Marine Sanctuary, the Vandenberg is the world's second largest intentionally sunk shipwreck. In her last mission as an artificial reef, this massive ship is already attracting a variety of fish and other marine life. Now, natural resources managers are trying to determine what impact this artificial reef has on fish populations and the health of the surrounding natural reefs.