Pitt,
Don't know of any specific wrecks, but many Pirates sailed the coastal waters of SC and GA. Blackbeard comes to mind and even Capt. Kidd came through the area before heading back to NY. I have heard stories of burried pirate treasure and I am currently working on a very specific one. I have a very interesting map on Scrimshaw tusk from the early 1700's. As I know more or if I find something, you guys will be the first to know!
Where did your Father find the Dubloon? In the water or on land? What general area or town?
I live over in Beaufort, SC and am currently working some wreck sites offshore. There are several intersting wrecks down around Tybee Island (possibly a Spanish Galleon).
Good Luck,
Robert in SC