This is a pristine island, a National Seashore, in southern Georgia, located between the Intracoastal Waterway and the Atlantic.
Leave the Waterway at Fl.R#40, at Mile 711, and proceed NNE for 1.3NM, keeping about 200yds from the shore of Cumberland Island. Anchor in sand opposite the National Seashore Visitor's Center. Dinghy ashore and walk from the Visitor's Center 1000yds along an easy path through the live oak forest, across the island to the pristine Atlantic beach which stretches 14 miles from Cumberland Sound almost to St.Andrew Sound.   Enjoy the peace of the forest and almost deserted beaches; study the interesting flora and fauna of this sanctuary. If you are fortunate you will see the wild horses that roam the island.

The Dry Tortugas are the only tropical islands within the 48 states. This is a National Park and a protected area, no commercial fishing is permitted. The only residents are the National Park Service personnel.
There is a protected anchorage, which is used by fishing fleets during inclement weather, close to historic Fort Jefferson, which itself is worthy of a visit. Enjoy warm weather and swimming in crystal clear water, even when Florida is hit by a cold spell! This is not surprising when you realize that Havana is closer than Miami. Bush Key, which protects the anchorage from the north, is a protected nesting area for terns. They share the islands with hundreds of pelicans and other sea birds. The waters are teeming with fish. If you're lucky you will see tortoises swimming along, quite unconcerned by the anchored boats. No supplies, not even water, are available in the Dry Tortugas. Bring some extra beer. Commercial fishermen, anchored for the night, will often trade a fresh catch of fish, shrimp, and sometimes lobster, for cold beer!

See a detailed account of a sailing trip to the Dry Tortugas in April 2007. with charts and many photos.

In settled weather, visit Loggerhead Key, 3 NM west of the Fort, and its pristine deserted beaches and fantastic snorkeling among coral reefs. The best snorkeling is off the beaches on the west coast, great areas of staghorn coral. Anchor in sand close to the jetty on the east coast, avoiding clumps of coral. Then dinghy ashore and explore. The only people on the island are coastguard personnel at the lighthouse.

N.O.S. Chart 11438. Start approach to Fort Jefferson anchorage from S. of "Fl.R #2" at 24deg37.5'N 82deg49.8'E., Then 2NM at 298Mag to "Fl.W #3", then 258Mag for 0.78NM to Red Marker #2, then follow the marked channel to the anchorage SE of Fort Jefferson and S of Bush Key, hard sandy bottom, make sure anchor is well dug in. Because of strong tidal currents, a Bahamian moor is recommended. The distance from Key West is 70NM. To reach the anchorage before dark you must leave Key West before sunrise. The only possible anchorage on the way is at Boca Grande, close to the Marquesas Keys, a group of tiny islands about half way.

The approach from the west coast of Florida is an overnight voyage. Leave Fort Myers no later than noon. The voyage is straightforward. Make sure you stay to the east of the yellow buoys "L" and "M" at 24deg 42'N 82deg 46'W and 24deg 40'N 82deg 46'W respectively, then proceed to buoy "O" before turning west to R2.
The experienced sailor coming from the north might try another approach. Head for yellow buoy "I" at 24deg 43.5'N 82deg 52'W. Then proceed directly S, keeping a sharp lookout for shoals and reefs, just as you would approaching any island in the Caribbean. At 1NM north of Fort Jefferson, look for day marker on Middle Ground Shoal and leave it to starboard. Then approach Red Marker #2 for the entrance channel. I have used this approach several times, in both directions. There are no problems in good light.