There are many unmanned light towers stretching all along the coast of Florida from Miami to as far as the Dry Tortugas. These mark and protect the network of coral reefs below the surface, and serve primarily as aids to navigation.

However, Florida “insiders” also know they serve another maybe less intentional purpose. These unmanned lighthouses also delineate some of the best dive and snorkel sites in the area!

It is no wonder that the Key’s reef lighthouses have become super popular among diving and snorkeling aficionados. These light towers were designed to mark the many reefs and shoals along the route to the keys. Which means the waters just below are teaming with an abundance of corals and marine life which present amazing opportunities for both the beginning snorkeler out on a day charter, as well as challenges for the advanced open water SCUBA diver.

Diving the Florida Keys

Also, because of their very nature as navigational markers, these sites are easy to find and reach by almost any recreational vessel during fair weather conditions.

Here are the GPS Coordinates for some of the most popular lighthouse dive locations from Key Biscayne to Key West — north to south.


GPS Coordinates — Lat 25ª15.1’ / Lon 80º19.5’ — Fl (3) R SEC 100 ft — 13M

Carysfort Reef Light Tower

Carysfort Reef Light Tower


GPS Coordinates — Lat 24º54.0’ / Lon 81ª44.1’ — Fl (4) 60s 136 ft 13M

Alligator Reef Lighthouse

Alligator Reef Lighthouse


GPS Coordinates — Lat 24º42.4’ Lon 81º13.4’ — Fl (5) 60s 142ft 12M

Sombrero Key Lighthouse

Sombrero Key Lighthouse


GPS Coordinates — Lat 24º34.2’ / Lon 81º38.2’ — FL (5) 3 R s 12M

Snorkeling Around American Shoals Light Tower in the Florida Keys

Snorkeling Around American Shoals Light Tower in the Florida Keys


GPS Coordinates — Lat 24º30.1’ Lon 81º59.5’ — FL (2) 15 SEC 11M


Aids To Navigation for Motor Yachts

While the Keys light towers can be used to find some great diving opportunities, they are primarily there to function as what are known as Aids To Navigation, or ATONs. It is important that all boaters and yacht owners are aware of ATONs, and how to use them to successfully and safely navigate.

Some are not nearly as obvious as the large key lighthouses, but they all serve an important purpose! The U.S. ATON system is maintained by the U.S. Coast Guard. It consists of visual, audible, and electronic signals which are designed to assist boaters in the process of navigation. ATONs include: buoys, day beacons, lights, lightships, lighthouses, radio beacons, fog signals, marks and other devices used to provide “street” signs on the water. The aids to navigation system is not intended to identify every shoal or obstruction to navigation which exists in the navigable waters of the United States, but rather provides for reasonable marking of marine features as resources permit.

ATONS are “coded” with odd and even numbers, red and green colors, and other markings.

USCG installing a Lighted Aid to Navigation

USCG installing a Lighted Aid to Navigation

A complete guide to understand symbols and colors of the various ATONs and what they mean, has also been published by the USCG.

On Demand Yachting Provides Peace of Mind

Using navigation markers to find interesting yachting destinations, and to make sure you can avoid hazards, is only part of the equation of enjoying the yachting lifestyle as safely as possible.

In the unlikely event it is ever needed, you must also ensure that you have all the right safety gear on board, and it is always ready and operational. That means PFDs need to be checked and replaced, fire extinguishers maintained and recharged as necessary, first aid kits restocked, etc.

Also, tantamount to avoiding accidents and other trouble at sea, is making sure your yacht is clean, detailed, and properly maintained. Maintaining your yacht’s safety gear, and ensuring that her engines and other critical systems are always at operational readiness is just one of the services you can count on from our On Demand Yachting Solution.



Operating a motor yacht can be costly. You can reduce your expenses, and avoid costly repairs by keeping her well maintained. On Demand yachting from FYM can help. If you would like to learn more, or if you have any questions or comments about this blog post, do not hesitate to contact our Yacht Management specialists, or call us at (954) 900-9968.