National Park Service
Windjammer Wreck School of fish underneath a wreck Diver with a Goliath Grouper Porkfish and Snapper fish Baby Turtle with Fort Jefferson in the background at sunsetCoral reefs with Loggerhead Key lighthouse

Diving in Dry Tortugas National Park

Diver above a stand of soft coral Diver above a stand of soft coral

If one could to come back to life in a new form, one could do worse than to return as a frigate bird soaring on the thermals that arise from the Dry Tortugas, 65 miles west of Key West, Florida. These diminutive islets, some of which appear and disappear through the decades, have no fresh water (hence the “Dry”) and no arable soil. But if you were a frigate bird, what would interest you is what interests a diver-not the forty acres of sand that comprise seven islets, but the 67,000 acres of underwater coral reefs and seagrass beds, brimming with edible fish, mollusks, and crustaceans, that surround them.

These reefs lie in the Gulf of Mexico at its juncture with the Atlantic Ocean and Caribbean Sea. The Florida Current, rich in sea life, wraps around them before heading through the straits of Florida to join the Gulf Stream and curve north along the Eastern Seaboard of the United States.

In the early 20th century, the islands played host to a Carnegie Institution Marine Laboratory and were declared a preserve and breeding ground for birds. Fort Jefferson and the waters around it were designated a National Monument in 1935 and upgraded to National Park status in 1992 in recognition of their important reef habitat.

On land and underwater, the relics of human dramas that have played out in this unique place over the course of half a millennium are everywhere evident, as the natural ship trap formed by the atoll-like configuration of islands has been the site of over 250 marine disasters. The half-buried remains of Spanish galleons lie in the shadow of the rusted hulks of iron-hulled clippers and steamers.


Location: Islets near Key West, FL
Skill level: Intermediate
Access: Boat or limited shore
Dive support: Key West
Best time of year: May-September
Visibility: Good to excellent
Highlights: Shipwrecks and marine life
Concerns: Fire coral, barracuda and sharks, currents
Rules and Regulations

Dive Site MapDry Tortugas Dive Site Map Texas Rock Pulaski Shoal LIttle Africa Windjammer Wreck Moat Wall Long Key Reef

Dive Overview

Diving this park is a logistical challenge, as the Dry Tortugas can be reached only by plane or boat. Likewise, there are only two ways to stay out there, on a boat or at one of 10 primitive camp sites on Garden Key. (These are first-come-first-served, with no fresh water or food available.)

A park visitor can opt to fly out by commercial seaplane from Key West or go by private boat or several charter boats that operate from Key West and Naples, Florida. For the scuba diver, boats are more feasible than the sea plane. If all you want to do is snorkel and if you are staying only a day or two, the seaplane is fine. On the other hand, if you plan to do some serious diving and want time to fully explore the area, consider the live-aboard charter boats.

The varieties of diving available here are as diverse as the environment itself. There are dives and snorkeling sites suitable for the beginner or small child (yet satisfying to experienced adults) easily accessible by boat from the park headquarters. Shore diving is limited to the Fort Jefferson and Loggerhead Key area. Just outside the park boundaries the adventurous advanced diver may find water over a 100 feet deep with strong currents and large predators of the sharkish persuasion. All dives, even under the fort pier, may feature one or more large barracuda. Although we see no significant danger from this aspect of diving in the park, fear of barracuda could spoil the fun for some. If one is particularly squeamish about finned biters, the Tortugas may not be for you.

When you leave for the Tortugas, remember to take all you'll need in spare parts and sun gear-there are no stores in the Tortugas. Don't be blasé about marine life here; divers have been stung by scorpion fish and are routinely "burned" by fire coral, described below.

Perhaps our strongest admonition is in regard to the currents. It is easy to take for granted the benign nature of such a warm, clear diving environment. Be sure you can return to your boat after the dive-being washed several miles out into the Gulf is a frightening and potentially life-threatening experience.

One marine hazard the diver encounters while diving throughout the Tortugas is fire coral. Though not really a coral at all, fire coral does resemble true coral, but is a hydrozoan, in this case growing very opportunistically over dead soft and hard coral as well as shipwreck parts. But be careful: if you touch it, it burns like fire. The wound you get will depend a lot on how allergic you are. Although painful, the wound is generally not serious.

Before beginning your dives, stroll the fort and visit with the rangers. Learn about any new regulations or prohibitions, and ask for up-to-date hints on diving conditions at various sites. The main concerns they will have is that you observe the prohibitions against spear fishing and lobstering in the park, that you do not remove anything from historic shipwreck sites, and that you observe safe diving practices including display of a dive flag.


Dive Sites


The most popular dive in the park is the wreck known as the Windjammer. Its real name was Avanti. Built in 1875, the three-masted, iron-hulled, sailing ship wrecked on Loggerhead Reef in 1901 on its way to Montevideo with a cargo of lumber. Before diving this site, be sure to pick up a laminated underwater map at the visitor center. This map will provide you with a self-guided tour of the wreck and allow you to make sense of what you are seeing. Depths on this site range from zero feet, where a small piece of wreckage actually breaks the surface, to 20 feet. It is a perfect place for snorkelers and scuba buffs to dive together. The best visibility on the site is during flood tide. The wreck has the greatest relief from the bottom and the most marine life at the very bow and the very stern of the wreckage. Consult the map to see how to locate those points since the ship is broken in half and you may become a bit confused without the guide. The site is a veritable aquarium of reef-dwelling, free swimming, and benthic (bottom) life. The structure serves as an artificial reef attracting a host of fish ranging from 200-pound jewfish to small tropicals.


Located off the north side of Loggerhead Key, this area is protected, shallow, and calm-a great place for snorkelers, and under most conditions, for children. Juvenile barracuda, lobsters, corals heads, soft corals, and tropical fish are usually visible.


This area is almost due north of Garden Key in about 55 feet of water. It consists of a huge mound of coral that emerges from the sand at about 55-60 feet of water and rises toward the surface to a depth of about 35 feet. The reef is rather isolated and is surrounded by sand. It takes a full dive to swim around the mound.

As you slide over the side of your boat, you may be immersed in a cloud of fish that are stacked up from the top of the reef almost to the surface. At first glance, they seem to be a fluid extension of the coral. Because the mound protrudes from a much lower reef, it is a magnet for marine life. On the north side of the reef is a forest of deep water sea fans that will rival anything to be found in the Caribbean. If you carefully investigate some of the nooks and I crevices in this area of the reef, you will find some rare black coral.

For the underwater shutterbug, this is a great place to photograph corals. With the exception of elkhorn and staghorn, almost every species of stony coral can be found here. In fact, this area is used as a coral growth monitoring station for ongoing research. If you happen on some obviously manmade apparatus while exploring this reef, it is probably part of this program. Please do not disturb any, of these sites as you could be harming some valuable environmental research.


This area marks the eastern boundary of the park. A navigational light tower marks the shoals themselves. Here the reef consists of scattered very shallow coral heads. In the days before navigational aids and accurate charts, these shoals claimed many ships and as a result, the diver can find the scattered remains of a wide variety of shipwrecks. When diving these sites, please remember to leave all the artifacts where you find them. This courtesy will allow other divers who come after you to enjoy the same sense of discovery. It is also against the law to remove any cultural artifacts and this particular law carries some serious penalties for divers who ignore it.

For more adventuresome diving, go just beyond the boundary buoys in about 75 to 80 feet of water and follow this depth curve looking for changes in reef elevation. It should not take long to find open ocean critters that will make for some exciting diving. Be very careful of the currents out here, as they are strong and variable in direction. As you descend into the deep blue water, you can expect to see very large grouper, and abundance of snapper, and often sharks. Black tips, hammerheads, bull, and nurse sharks are all common sights out here. In addition, you may also get to see turtles and some large formations of eagle rays. The diving out here is not for the timid or the novice diver. Be sure you know what you are getting into before you take the plunge. If you get yourself into trouble out here, you are a long way from help.


This reef is just to the south of Long Key. It starts in about 35 feet of water and extends out to about 65 feet of water. It is heavily developed coral reef with deep surge channels running north and south between ranges of coral. You will see big star and brain coral heads along with some nice areas of plate coral. Visibility in this area is not as good as in other parts of the park because it does not get the strong flushing currents that typically occur in other areas. If you catch it when the visibility is good, the dive is great for novices and experts alike. The best technique is to use the surge channels as road maps to keep a point of reference of where you are on the dive. Try diving down one channel and coming back another, keeping count of how many you crossed. Once you get back to your starting depth and cross the same number you did on the way down, you are back where you started. Well, at least it works most of the time.


This is a rare treat. Outside the moat wall of Fort Jefferson an eerie sense of history meshes with the natural wonders of the underwater world. It is safe enough for kids who are comfortable in the water and exciting enough to stimulate the kid in the most jaded adult.

If you are new to night diving, we offer two bits of advice. Snorkel or dive the area first in the daylight, so it won't be totally foreign to you when the lights are out. And don't forget to bring a strong dive light. The best place to enter the water is the beach on the west side of the fort. From here swim along the moat wall to a point about halfway around the fort and then come back the same way. The water depth will vary depending on the tide but shouldn't exceed six to eight feet. You will find many creatures out and about that you will never see during the day. The octopus is a common sight, slipping along the bottom searching for some choice mollusks for dinner. The basket starfish is another creature that is common at night but very hard to find during the day. These critters usually hang out on the sea fans and look like a mass of thin starfish legs that are suffering from total confusion.
The fish are much more docile at night and can be approached much closer than during the day. Be careful not to shine your light directly at the fish as this both startles them and temporarily blinds them. They will then dart off and run straight into a coral head or the moat wall. Remember we are only visitors here and should respect those that make this place their home.

Other things you are apt to see include lobsters, decorator crabs, arrowhead crabs, coral shrimp, and squid. Daytime diving is for the underwater vistas; night diving is a more intimate experience. Your world has shrunk and you need to bring your focus in to a smaller field of vision. In that reduced field, you will begin to see much more detail.



Diver-down flag must be displayed while divers are in the water.
It is forbidden to remove any cultural artifact from park waters. This includes any part or piece of a shipwreck.
No spearfishing or game taking of any kind is allowed while diving. Noncommercial line fishing is permitted but you must have a valid Florida fishing license.
If you spearfish or take lobster outside the park and then return inside park boundaries, you must call and notify the ranger on VHF radio or proceed directly to the park headquarters and have your catch verified before you go back out diving in the park.
Chasing marine life, including sea turtles, by boat or in the water is strictly forbidden.

Last Updated: August 16, 2016