Snorkeling in Marathon FL| Best Locations and Boat Trips

If you want to include snorkeling in the Keys around Marathon on your vacation itinerary, this guide will take you through all the best spots in the area. We love snorkeling the Florida Keys when in Marathon, and have taken recent trips to the locations featured here.

When you want to go snorkeling in Marathon, Keys and reefs to consider nearby include Sombrero Reef, Coffins Patch and Looe Key Reef. If you want to snorkel from the shore, head to Bahia Honda State Park, Horseshoe Beach or Sombrero Beach. There is more information on each of these in this article, including what you can expect to see at each location.

We’ve also included details of the most popular trips for snorkeling Marathon Key, FL as part of a group tour. These run to various locations, including the two best spots in the area – Looe Key Reef and Sombrero Reef. Having taken trips to these places with the companies mentioned, our recommendations are based on first-hand experience.

Our favorite spot near Marathon is also our favorite snorkeling spot in all of the Keys and one of our favorites in the Caribbean in general- Looe Key! The other spots are good, but this is the Can’t Miss spot!

Our top tip for those who wish to enjoy snorkeling in Marathon FL is to choose a dedicated snorkel tour instead of a snorkel/dive combo. As the latter also cater to divers, they may well take you to a deeper part of the reef. While you can still see creatures and corals, they will be much further down, instead of close to you and near the ocean’s surface.

If you’re interested in the best snorkeling near Marathon, read on so you can plan your perfect underwater adventure!

In this post:



Sombrero Reef

Sombrero Reef Lighthouse

This reef is named after the Sombrero Key Lighthouse, and the area around the lighthouse is a fun place in which to enjoy snorkeling in Marathon, Florida. Sombrero Key Sanctuary Preservation Area and can be found 3.5 nautical miles from Boot Key.

The reef has a good quantity of healthy coral, and you can expect to see lots of colorful fans and tropical fish during your visit. When we visited, one person in the group even managed to spot a nurse shark. 

Sombrero Reef is known for its range of corals, including boulder, blade fire, pillar, lobed star, elkhorn and branching corals. It’s a fabulous reef formed like a spur and groove, and if you’re lucky the water can be crystal clear here, enhancing visibility.

Sombrero Reef

As well as colorful fish and various corals you may see other sea life such as sponges of all shades, sea fans and plumes and numerous kinds of fish. Lots of parrotfish inhabit the area, including princess, midnight and rainbow parrotfish. 

Angelfish are also a common sight, and resident species include French and queen angelfish. You may also spy barracuda, hogfish, grouper, damselfish, snapper, scorpionfish, grunts, butterflyfish, blue tang and sergeant majors.  

Some are fortunate enough to come across a sea turtle or two. The depth varies between around 10 and 20 feet, and there are some arches to swim beneath plus small canyons to explore if you’re a more experienced snorkeler. 

Much of the best Marathon Key snorkeling can be found at Sombrero Reef, so don’t miss the chance to visit it if you can. Due to the distance from shore, you’ll need to take a private or group boat trip out there.  We went with Starfish Snorkeling, and it was a great trip out to the reef on a catamaran.

You can also do some shore snorkeling near Marathon, FL from Sombrero Beach – there’s more detail on the underwater life found at this separate location below. 

Sombrero Beach

Sombrero Beach Marathon
Photo credit: Rachael Cash, Getty Images

Note: Shore snorkeling in the Keys is nothing like the reef. It’s great for beginners and a fun addition to beach days though!

Like the reef of the same name, Sombrero Beach is also one of the best Marathon Key snorkeling spots from the shore. Although the sea life you’ll see here is much more limited than at off shore locations like Sombrero Reef, it’s still one of our favorite places to snorkel in the Keys from shore, not least because of the beautiful white sands. 

If you are planning a beach day, do pack your snorkel so you can have a look underwater during your visit. As it’s shore snorkeling available here, there aren’t large formations or fish to see, but you can expect to spy some smaller corals and a few colorful fish, especially on a clear day.   

Marathon FL Beaches
Photo credit: John Gallant, Shutterstock

Some of the finest shore snorkeling in Marathon can be found close to the rock shelf, as creatures such as sea urchins sometimes frequent the area. 

Bahia Honda State Park

Bahia Honda Beach

Note: Shore snorkeling in the Keys is nothing like the reef. It’s great for beginners and a fun addition to beach days though!

Few who visit the Middle Keys want to miss Bahia Honda State Park. The views from both land and under the sea are beautiful, and again the water clarity can be very good here. 

The park is located on Big Pine Key, right by mile marker 37. There are three beaches to check out, so if you are visiting Bahia Honda make sure you take or rent a snorkel. Snorkeling at Calusa Beach is known to be the best at the state park, especially around the rocks.

Boat trips to the National Marine Sanctuary at Looe Key also depart from Bahia Honda, making it simple to combine some of the top Marathon Florida snorkeling spots in one hit.   There is also a snack bar, gift shop and kayak hire available at the park, and it’s a popular place for fishing, cycling, camping and swimming in addition to snorkeling.

One of the key advantages of Bahia Honda State Park snorkeling is the fact that you can snorkel from the shore here. It is therefore ideal for rookies, who can practice here before taking a boat trip out to one of the reefs that lie further from land.

Those snorkeling at Bahia Honda may see some small fish in the area close to the rock jetty. There are no corals to be seen when snorkeling from the shore, and you’ll generally come across a lot of seagrass. 

As there are lots of other things to do at Bahia Honda it’s well worth a day of your time during a vacation. The beaches are lovely to laze around on even if you don’t feel like doing much, or you can walk, swim, cycle or kayak if you do crave activity. 

Bahia Honda also boasts a historic bridge and a range of award-winning beaches. The best snorkeling spots include Sand Spur Beach on the Atlantic coast and Calusa Beach on the gulf side.

Coffins Patch

The Coffins Patch Sanctuary Preservation Area offers some of the best snorkeling in Marathon, FL. It comprises a collection of shallow patch reefs, which are located around four nautical miles from Key Colony Beach in the Middle Keys and is also reachable when snorkeling in Islamorada

There are lots of species of fish to see as well as plenty of corals. The area is known for pillar coral in particular, and the most impressive formations can be found on the western side, at a depth of around 25 feet. Boulder corals reaching up to three feet may also be seen.

Other sea life you can expect to see in their natural habitat include nurse sharks, lobster, stingrays, butterflyfish, grouper, jacks, moray and tangs. 

There are half a dozen patch reefs to explore in this Sanctuary Preservation Area. As they’re found at varying depths, each is different from the next. For snorkelers who want to spend plenty of time discovering underwater Florida, this is one of the best Marathon snorkeling spots to aim for.

If you take an organized boat trip, you’ll most likely be taken to two or three parts of Coffins Patch. One of the most often visited is an area known as The Stake, which is so-called due to the metal post rising above the surface of the water here.

Coffins Patch is a few miles from the shore, and is usually reached from the island of Key Vaca that lies within the Marathon city limits. As these patch reefs are fairly close to the barrier reef, more species can be seen and often the water is clearer too.

Some of the more unusual creatures spotted at Coffins Patch include the puddingwife parrotfish, tiger grouper, porkfish, yellowhead wrasse, bicolor damselfish, spotfin or foureye butterflyfish, large spotted moray eels and lobster. 

Like other areas around the Keys, Coffins Patch was once the site of a shipwreck, and is said to be named for the fact that the vessel concerned was carrying coffins as its cargo.

Horseshoe Beach

Horseshoe Beach

Horseshoe Beach is really just a small, rocky and slightly muddy spot by the bay, but it makes a good place to enter the water. The name comes from the rock jetty that protects the area, which is shaped like a horseshoe encircling a lagoon. 

Apart from some smaller fish and corals, manatees are sometimes spied at Horseshoe Beach. Being a bit off the beaten track, it can be a good place to go if you want to avoid the crowds, or if visibility is poor at the local sites that lie further from land. 

Horseshoe Beach is located close to mile marker 35 on Big Pine Key. The lagoon is around 30 feet deep in the center, and coral was excavated from the site when the Overseas Highway and bridge were built.

Those who do visit Horseshoe Beach may be rewarded with sightings of barracuda, parrotfish, rays, snapper and other tropical fish species as well as jellyfish. As it’s sheltered, it’s a good spot for beginners or families – or when inclement weather strikes the place you planned to go to.

Looe Key Reef

Looe Key Reef Shark

If you have just one go at snorkeling in Marathon, Florida, make it Looe Key. This place quite simply offers the best snorkeling in the whole of the Keys, so it’s not to be missed. You can venture up to Looe Key when planning on snorkeling from Key West as a home base. It’s worth the extra boat ride or drive. According to several people who run snorkeling trips in Marathon, FL, and the rest of the keys, this is the best place to snorkel, and we would agree!

You can take trips out to Looe Key from Bahia Honda. When we took one we were lucky enough to see several reef sharks plus tons of fish, including the more unusual Goliath grouper.  

During our trip, the captain told us that eagle rays and even hammerhead sharks are sometimes seen at Looe Key. So it’s maybe not the best snorkeling Marathon Key destination for absolute beginners, who might get spooked by seeing bigger sea creatures.

Looe Key Fish and Coral
Snorkeling Marathon FL

The waters are deeper at Looe Key Reef than elsewhere, and as it’s close to the barrier reef the area is also more exposed to swells and currents. This explains why it’s number one among Marathon snorkeling spots for those who wish to see larger forms of sea life.

Looe Key is a large reef, so it would be easy to spend a lot of time here. As depth and visibility vary, you may see different species depending on which parts you snorkel at. Tarpon, rays, barracuda and even colossal grouper tend to frequent the deeper areas, while in shallower waters you may be more likely to see smaller fish.  

Witnessing a colossal grouper swimming around is quite something – these huge fish can be as long as a man is tall, weighing in at around 150 lbs or more. 

Looe Key Grouper
Looe Key Deep Shark

Giant parrotfish are also quite a common sight at Looe Key Reef. They are huge in comparison to most parrotfish you see, similar to the ones we’ve seen in Bonaire that are the size of medium dogs.

As well as larger fish, you can expect to see a wide variety of species at Looe Key. There are also plenty of colorful corals. The all-round experience offered makes this reef a hotspot for snorkeling in Marathon Key, Florida.


There are lots of Marathon Florida snorkeling tours you can book onto. We have personal experience of using Spirit Snorkeling in Marathon and have also taken one of the Bahia Honda trips to Looe Key.

Whichever you book, you may not know ahead of time where the tour is going until the actual day. This is because a captain will make their decision based on current weather conditions.

It is, however, still a good idea to plan in advance. You can easily check where each tour usually goes and plan what you want to see accordingly. 

The precise locations you’ll stop at will also depend on mooring ball availability. Each area is a bit different, so some of where you can snorkel and what you might see will vary depending on which mooring ball is allocated on the day. 

Every of the group tours we’ve been on required us to stay within about 50 yards of the boat, so on a tour with other people you will also be affected by that restriction. Having said that, it is to keep you safe! 

Some of the best known trips are run by Starfish Snorkeling and Spirit Snorkeling in Marathon, Florida, as well as the Looe Key tours operated by Bahia Honda Snorkeling Tours.

Starfish Snorkeling

We took a tour to Sombrero Reef with Starfish Snorkeling in Marathon FL. Traveling on a catamaran – ‘The Starfish’ – this trip includes all the gear you’ll need, such as a mask and flippers

As this tour is specifically aimed at snorkelers, no diving equipment is even carried on board. This is a good thing, as trips that incorporate scuba diving as well as snorkeling tend to visit deeper waters, but these aren’t the best option when you want to snorkel rather than dive.

You may see dolphins and turtles on your way out to sea and once you arrive prepare to be dazzled by schools of tropical fish and masses of colorful corals. If your plans for snorkeling in Marathon FL include Sombrero Reef, this is the trip we recommend taking, based on our own positive experience. 

Check it out on Tripadvisor here.

Spirit Snorkeling

If you want to take a look at an alternative, some of the best Marathon snorkeling tours are operated by Spirit Snorkeling. The company running these is also known as Captain Pip’s, and they even offer use of a private island, Money Key, for the day.

You can book onto Spirit I or Spirit II. The former focuses on snorkeling at Sombrero Reef, while the latter is a more rounded experience that may also include relaxing at the sandbar, kayaking and paddle boarding. 

Check it out on Tripadvisor here.

Bahia Honda Snorkeling Tours

We took this trip to Looe Key when snorkeling the Marathon Florida Keys. It’s one of just a few tours that will take you to one specific place, so unusually you do know exactly where you’re headed before the day of travel.  

No tour operator can control the weather, though, so if the state of the sea isn’t suitable for a safe trip on the day, it will be canceled rather than rerouted to another location. 

These tours are operated by a concession at Bahia Honda State Park, and are scheduled to run daily when weather permits. Trips depart during the morning or afternoon and you can rent all the equipment you need (extra charges apply). 

Click here to find Looe Key tours from Bahia Honda State Park.

Other options

Should you wish to explore other options, such as fishing trips with Sea Dog Charters in Marathon, Florida, you can find out all about these via sites such as TripAdvisor.

You could also think about chartering a boat for the day privately, as that way you can see exactly what you want to. This allows you to spend as much or as little time at each destination as you like, and can be more affordable when shared between a few people. 


If you’re headed to the Florida Keys on vacation, don’t miss the chance to fit in some snorkeling – especially if you’re new to the sport. With great shore snorkeling available around the Middle Keys, it’s the ideal place to learn.

There are great sites to keep more experienced snorkelers happy too, however. If you’re a big fan of underwater exploration, don’t miss the chance to visit Sombrero or Looe Key Reefs. At the latter in particular, you might just have a close encounter with the kind of creature you’ve never even laid eyes on before!

Looking for more ideas for your next Florida Keys trip??? Check out all of our Florida Keys Guides HERE!

About the author
Kristin Young