At least a full day:
Garden Key and Fort Jefferson -- a full day,
Accommodations
Camping:
Camping is permitted only on Garden Key.
The 10-site primitive campground is open year round and is first come first serve.
A group site is available for 10-40 people and must be reserved in advance by phone 305-242-7700.
No fresh water available on the island.
A policy of "pack it in , pack it out" is strictly enforced.
Campers must bring all of the water and food needed for their entire stay.
Saltwater flush toilets are available.