Okeechobean Sea

The Okeechobean Sea was a Cenozoic eutropical subsea, which along with the Choctaw Sea, occupied the eastern Gulf of Mexico basin system bounding Florida.

The Okeechobean Sea was a named for Lake Okeechobee of southern Early Oligocene Florida. It occupied southern Florida from what is now Tampa, Florida to the Kissimmee River and to Martin County on the east and southward across the Everglades to the tip of Florida. The Okeechobean (including its subseas) survived until the making it the longest-lived paleosea in eastern North America.

The Okeechobean Sea was divided further into two groups of a combined 10 subseas based upon marine fauna. These subseas were named:

The Dade Subsea was named for Dade County, Florida fossil reefs and is contemporary with the Bainbridge Subsea of North Florida. It is the last platform created from carbonate deposits and the predecessor of the recent Florida peninsula. It was formed out of the meteor impacts and tsunamis of the colder Eocene. By the mid Rupelian, the global climate warms and Florida consists of just Orange Island, a somewhat long island with coral reefs extending as far north as Alabama and Georgia forming the Salt Mountain formation and Flint River Formation respectively. Along its west coast lay the Pasco Reef System. separated from the mainland by the Gulf Trough or Suwannee Strait also with coral reefs. Orange Island lay just 150 km (93 mi) from Georgia. Two deep carbonate features will eventually become the substructure of the Everglades.

...
Wikipedia