The historic lighthouses along the Florida Keys are not like those that you’ll see in other places along the coast. Except for the small tower in downtown Key West, the most notable ones are located far offshore. Since the first Spanish galleons began plying the waters of the Gulf Stream in the 1500s, the Florida Reef has proven a formidable foe.

While the Gulf Stream current provides a high-speed boost for ships traveling eastbound out of the western Caribbean or from Havana, a deadly, keel-crunching reef lies invisible, right under the surface at the edge of the deep water.