The history of lighthouses at Cape San Blas is a curious and checkered litany of bad decisions and bad luck. The light established in 1847 was blown over in a storm four years later. A second tower lasted only a few months before receiving the same treatment. The tower was rebuilt in 1859, only to be blown up by the Confederates during the Civil War. Repairs after the war were followed by 15 years of relative calm for Cape San Blas. By 1880, however, the tower was surrounded by encroaching water and eventually toppled over.
The present 90 foot, pyamidal skeleton tower was completed in 1885 and fitted with a third-order lens. Within a few years it too was threatened by water, and Congress authorized funds to move it. The move to a new location to Black's Island was begun, but the Lighthouse Board changed its mind and relit the tower back in the original location. While the authorities fumbled along with new plans, the erosion reversed and the water receded. The story ends in 1919 when the waters returned and the tower was moved a quarter-mile to its present location.
I visited Cape San Blas to see the bi-valve clamshell lens, but after sneaking past the "authorized vehicles only" sign, I was disappointed to find the lens draped with a tarp. Thanks to Tom Liddle for the undraped photo.