Photo: Dpalma01, CC BY-SA 4.0Picture a 19th century brick fort on a tiny island, 70 miles of open water from Key West. You swim along the outside of its moat wall, where reef squid, nurse sharks and big groupers cruise the old stonework.
Fort Jefferson on Garden Key is the star. Its moat wall is covered in coral and sponges, and fish shelter in the crevices. Out at the old coaling dock, the pilings draw larger fish. Park staff list reef squid, nurse sharks and hogfish along the wall, and groupers, tarpon and barracuda around the pilings. The water is protected, so the fish are plentiful and used to people. It is shallow near the wall, but the open water beyond is deeper and the current can pick up.
The main snorkel. Swim along the wall to see reef squid, nurse sharks, hogfish and the old stonework. Inside the moat is closed.
The pilings of the old coaling dock attract groupers, tarpon, barracuda and the occasional shark.
The park's best-known shipwreck. Large fish gather around it and visibility is best at flood tide. It needs a boat to reach.
A shallow, calm coral reef that the park says suits snorkelers, including children.
A slow, brownish shark that spends the day resting on the bottom under ledges in Florida. It looks sleepy, but it can bite if grabbed.
Guardian rule: Never touch or pull a nurse shark's tail.
Ginglymostoma cirratum
A long, silver predator that hangs motionless near the surface and watches snorkelers with curiosity. It looks fierce but rarely bothers people.
Guardian rule: Take off shiny jewelry, which can look like a fish flash.
Sphyraena barracuda
A giant grouper that can top 400 lb and gathers on Florida wrecks and ledges. Protected from harvest in US waters since 1990.
Epinephelus itajara
Clawless lobsters with long antennae poking out from under ledges. Caribbean spiny lobster live on Florida reefs and California spiny lobster in kelp and rock.
Panulirus
A critically endangered turtle with a narrow, beak-like mouth and an overlapping, patterned shell. Hawksbills feed on sponges around coral reefs and are a rare, lucky sighting.
Guardian rule: Stay at least 10 ft away and report sightings to local turtle programs.
Eretmochelys imbricata
The turtle you are most likely to meet. Greens graze on algae over shallow reef and rest under ledges. In Hawaii they are protected and very used to snorkelers.
Spotting tip: Scan the rocky edges where waves wash over algae, and sandy cleaning stations where fish pick at their shells.
Guardian rule: Stay at least 10 ft away. Never block a turtle's path to the surface.
Chelonia mydas
Colorful grazers with fused, beak-like teeth. You can hear them crunch on coral rock, and much of the white sand on tropical beaches passes through them.
Scaridae
Rounded coral heads covered in winding grooves that look like a brain. Common on Florida reefs and slow growing, so a big head can be centuries old.
Diploria, Pseudodiploria, Colpophyllia
Sunken ships and historic wrecks that now work as artificial reefs, covered in coral and full of fish.
Guardian rule: Look, do not take. Historic wrecks in sanctuaries and parks are protected by law.
Live sea temperature, waves and wind for the next 7 days, with our snorkel rating for each day.
Calm Choppy Rough. Wave heights are offshore model values.
Loading tides…
Forecast: Open-Meteo. Tides: NOAA station 8724580. Model data, not a lifeguard report. Always check posted warnings.
Hand-picked tours that run here, ranked for small groups, a proper reef briefing and respect for wildlife.
by Yankee Freedom
Ferry departs 8:00 AM, arrives about 10:30 AM and leaves the fort at 3:00 PM. Includes breakfast snack, box lunch, snorkel gear, the park entrance fee and a 45 minute fort tour.
Park entrance is included and you can snorkel the outside of the moat wall on your own time. The park asks visitors to wear reef-safe sun protection.
by Key West Seaplane Adventures
About 40 minutes each way by air with at least 2.5 hours on the island. Adult fare; the $15 park fee is extra for ages 16 and up.
by Key West Seaplane Adventures
About 8 hours total with at least 6.5 hours on the island, enough for a long snorkel plus the fort. Adult fare; the $15 park fee is extra for ages 16 and up.
We may earn a commission when you book through these links, at no extra cost to you. It never changes which tours we pick. How we choose tours.
Apr to Aug is the calmest stretch, with warm water and the best visibility, although the ferry crossing is long in any month. Winter fronts bring rough seas and cooler water, and a ferry or flight can be cancelled for weather. Hurricane season (Jun to Nov) can close the park.
Mid-morning to early afternoon on the ferry schedule. The fort tour and lunch share the same window.
Visibility at the Windjammer wreck is best on a flood tide, according to the park.
Strong winter cold fronts and any day a hurricane or tropical storm is forecast.
| Row | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Snorkel conditions | Fair | Fair | Good | Best | Best | Best | Best | Best | Good | Good | Good | Fair |
| Water °F | 71 | 72 | 74 | 77 | 81 | 84 | 86 | 86 | 85 | 82 | 77 | 73 |
You can snorkel the outside of the moat wall without a guide, since gear comes with the ferry. There are no lifeguards. Use the buddy system. Beyond the swim area, currents can pick up and help is far away, and a dive flag is required outside the designated snorkel area.
Swim level: Comfortable swimmer
Dry Tortugas is almost 70 miles west of Key West. You can go by the Yankee Freedom ferry (about 2.5 hours each way), by seaplane (about 40 minutes), or by private boat. Most visitors do a day trip.
Parking in Key West is limited. Check the operator's directions page for where to park near the ferry dock.
Walk off the ferry onto Garden Key, then go through the fort or around it to the swim area. Snorkelers enter the water from the beach by the moat wall.
About 150 minutes each way, roughly 70 miles. Boats leave from Key West Historic Seaport.
Park entrance is $15 per person for ages 16 and up, valid 7 days. Ages 15 and under are free. The Yankee Freedom ticket includes it.
Official fees and hoursChecked 2026-10-22. Fees change, so confirm before you go.
All coral, living and dead, is protected. Do not touch, stand on or collect anything, including shells and historic artifacts. The moat is closed to swimming. Fishing is closed in the Garden Key moat, spearfishing and lobstering are prohibited, and a Florida saltwater license is required for those 16 and older. Wear reef-safe sun protection.
Most visitors take the Yankee Freedom ferry from Key West, about 2.5 hours each way. The Key West seaplane takes about 40 minutes. Private boaters check in with a ranger on arrival. Camping on Garden Key needs the ferry or your own boat, since the seaplane does not carry campers.
Dry Tortugas is a national park, so federal rules apply on top of the Florida Keys sanctuary rules.
The moat inside Fort Jefferson is closed to swimming and snorkeling. Swim along the outside of the moat wall or around the south coaling dock pilings. Official rule
All coral, living and dead, is protected. Shells and historic artifacts are protected too. Look, but do not touch. Official rule
Standing can kill them. Float, or use a flotation vest to rest. Official rule
The Garden Key moat is closed to fishing. Spearfishing and lobstering are prohibited. A Florida saltwater license is required for visitors 16 and older. Check the park's fishing page for current rules. Official rule
The park asks visitors to wear reef-safe sunscreen or protective clothing in the water. You cannot buy any in the park. Official rule
Boats may only land at the dinghy beach near the government docks. Overnight anchoring is allowed only on sand and rubble within 1 nautical mile of the Fort Jefferson harbor light. Official rule
How snorkelers protect reefs · Choosing a reef-safe sunscreen
Park entry is $15 per person for ages 16 and up, valid for 7 days. The Yankee Freedom day trip started at $260 per person when we checked, and it includes the entry fee, meals and snorkel gear. A seaplane half-day was $527 per adult.
No. Swimming and snorkeling inside the moat is prohibited. The park recommends snorkeling along the outside of the moat wall or around the south coaling dock pilings.
The Yankee Freedom ferry takes about 2.5 hours each way. It departs Key West at 8:00 AM, reaches Fort Jefferson around 10:30 AM, and leaves at 3:00 PM to arrive back in Key West around 5:30 PM.
Yes. Key West Seaplane Adventures flies half-day (about 4 hours, at least 2.5 hours on the island) and full-day (about 8 hours, at least 6.5 hours on the island) trips. The flight is about 40 minutes each way. Seats are limited, so book early.
Yes, on Garden Key. Individual sites are $15 per night and first-come, first-served, with eight sites. The group site is $30 per night and needs a reservation. Bring everything, including water. The ferry carries only 10 campers a day, so book early.
Yes. Check in with a ranger on arrival at Garden Key. Overnight anchoring is allowed only on sand and rubble within 1 nautical mile of the Fort Jefferson harbor light. Land at the dinghy beach near the government docks and keep boats out of the swim area.
What we pack for every snorkel trip. Each link searches the category on Amazon so you can compare brands and prices.
Non-nano zinc oxide only. No oxybenzone or octinoxate, which Hawaii bans.
Shop on Amazon →The best sun protection is fabric. Less sunscreen in the water, less sunburn on your back.
Shop on Amazon →A low-volume mask that fits beats any rental. Short travel fins pack easily.
Shop on Amazon →An inflatable vest lets you rest without standing on the reef. Lifeguards love them.
Shop on Amazon →As an Amazon Associate we earn from qualifying purchases. Disclosure.
Looe Key is the Lower Keys' answer to the crowded Upper Keys reefs. The coral on this long spur and groove reef tops out only about 7 ft down. You…
Wild manatees drifting past your mask. Seahorses under a bridge. The only living barrier reef in the continental US. Florida packs all three into one…
We check fees, rules and access against official sources first, then local operators and recent visitor reports. Conditions change, so always follow posted signs and lifeguards. Spotted something out of date? Tell us.
