Snorkeling in Marathon FL – Best Spots To Visit

Snorkeling in Marathon FL provides the area’s visitors with the possibility of observing some of the most vibrant reefs of the Middle Keys. To see the healthiest corals and a good amount of marine life, signing up for a boat tour is necessary, but there are some beaches here whore shore snorkeling is also possible. To find out what spots to visit, here is our summary of the best ones!

Coffins Patch

One of the popular Marathon snorkeling spots is Coffins Patch Reef which lies between Duck Key and Marathon. In fact, it is not just one reef, but six smaller patch reefs close to each other.

The location got its name after a ship that wrecked here and was carrying coffins, but the small reefs have their own names too: Stake, Elbow, Donut, Three Bag Reef, Sand Circle and Pillar Reef/Outer Edge.

Shallow depths (between 10-40ft/m) and a vast selection of marine life make these reefs very enjoyable for snorkelers at all levels. Expect to see yellowtail snappers, grunts, trumpetfish, snappers, parrotfish, angelfish, lobsters and moray eels.

Coffins Patch Reef

If you visit Coffins Patch with an organized Marathon snorkeling tour, you will most probably stop at two or three sites depending on the weather and water conditions. The most visited spot is the Stake which was named after an iron pole sticking up above the water. This is the best snorkeling in Marathon FL for beginners as it is shallow but has a huge variety of corals and fish.

Sombrero Beach

The beautiful white sandy public beach of Sombrero Beach located just two miles off Overseas Highway at mile marker 50 is the perfect spot to go snorkeling in Marathon if you are a family with small kids or there are beginner snorkelers in your group.

Sombrero Beach Florida Keys
Sombrero Beach – Image source

Thanks to the calm, shallow waters, new snorkelers can easily learn here how to use their gear and observe Florida’s aquatic life. Between the rocks along the shore, one can find lobsters and fish species, while there is a possibility to see sea stars and sometimes even rays in the seagrass meadows.

Although the water can be murky near the shore, if you swim a little further out it gets clear enough to see fish and marine life.

Additionally, Sombrero Beach has various comfort features too like a big parking lot, restrooms, picnic area and playground so it is no surprise that it is a great choice for vacationers looking for the perfect place to spend a nice day at the beach.

Sombrero Reef

Situated east of Boot Key, at the edge of the Florida barrier reef, Sombrero is the largest reef in the Marathon area and is said to have the best snorkeling in the Keys by many. With shallow depths (6-60ft/1.8-18m), caves and canyons to explore besides thriving marine life, healthy hard corals and sea fans, this protected sanctuary preservation area must be on your itinerary when visiting Marathon. In fact, Sombrero Reef is considered to have the richest selection of fish and corals in Florida.

Although some people say that this Marathon snorkeling site is not as vibrant as it was once, there is still a wide variety of species to see here. On top of various soft and hard corals and the usual colorful reef fish (blue tangs, damselfish, parrotfish, angelfish, barracuda), nurse sharks and turtles also frequent the area.

If this is not enough, there is even a 142ft/43m tall lighthouse called Sombrero Reef Light standing here which makes this location even more spectacular! It is not only a prominent local landmark, but also the tallest lighthouse of the Keys!

Note: there are often jellyfish at Sombrero Reef but usually moon jellies are around that are not dangerous.

Delta Shoal

Not so far from Sombrero Reef, Delta Shoal is another Marathon snorkeling site that is worth a visit. With clear, current-free, shallow waters (15-25ft/4.5-7.6m) and good visibility, this location is suitable for novice underwater explorers.

The abundance of marine life is exceptional at Delta Shoal; the reason for the wide selection of fish and other species is that this area is very close to the nearby sanctuary preservation area of Sombrero Reef. Delta Shoal -however it is not a protected area itself- is also benefiting from this protection status and enjoys providing habitat for those species that otherwise would overflow Sombrero Reef.

What’s more, there is even an old slaver ship that ran aground here, the Ivory!

Author’s Tip: if you need help on where to stay when visiting Marathon, here are my top recommendations:

Ivory Shipwreck

Northeast of Sombrero Reef Light, at the western end of Delta Shoal lies an interesting wreck, the Ivory. Her origin is still not confirmed, but she is believed to be a slave ship because leg irons were found at the site.

The Ivory sunk in 1983 while carrying people from Africa. When the wreck was discovered, it was named Ivory because its artifacts included 12 elephant tusks.

At this Florida shipwreck site, the remnants rest in relatively shallow water (maximum depth is 15ft/4.5m) so snorkelers can enjoy exploring it too. The area is rich in seagrass beds and soft corals that attract a variety of fish.

Barracudas, surgeonfish, parrotfish, grunts, blue tangs can be seen at this Marathon snorkeling spot, sometimes nurse sharks too. There is even a 2ft/0.6m tall monument that was placed underwater to honor the slaves who died when the ship sunk.

Bahia Honda State Park

Just before reaching Big Pine Key near the old railroad bride historical landmark, Bahia Honda State Park is another shore snorkeling spot in Marathon. Featuring soft sandy beaches and shallow waters, this 500-acre state park is an excellent location for families to spend a great day at the beach to enjoy the sun and discover the marine life of the Florida Keys.

Bahia Honda State Park Beach

In my opinion, snorkeling at Bahia Honda is the best suitable for newbies to learn how to use their gear and move comfortably in the water. To enter the water, you have Calusa Beach/Loggerhead Beach on the Bay side and Sandspur Beach on the Atlantic side (carrying a dive flag is required when snorkeling here).

Unfortunately, you won’t find coral at Bahia Honda State Park only some juvenile fish, sea stars, and queen conches in the seagrass and between the rocks. If the aquatic life would not satisfy you, it is easy to book snorkeling trips to the nearby Marathon reefs at the concession service providers on the site (Coral Reef Park Co).

Note that there is very little shade on the beaches of Bahia Honda State Park so make sure to pack your own cabana or umbrella. Gear rental for water sports including snorkeling is available tough and there are kiosks to grab some snacks and drinks.

The Marathon area has some additional shallow dive sites like East Washerwoman Shoal and East and West Turtle Shoal. These locations are better known as fishing spots but diving and snorkeling is also possible at them.

Marathon Snorkeling Map


Can you snorkel off the beach in Marathon?

Shore snorkeling in Marathon is possible at Sombrero Beach and at Bahia Honda State Park. These spots do not offer exceptional snorkeling but are suitable for beginners and for families with kids thanks to their shallow, warm waters and gentle conditions.

Is Marathon Florida good for snorkeling?

The snorkeling sites near Marathon offer some of the healthiest corals and most vibrant marine life to see in the Middle Florida Keys. The area’s reefs are exceptionally healthy because most of them are situated in deeper waters and get nutrient-rich currents.

What reefs are near Marathon?

There are several reef snorkeling sites near Marathon that are accessible with short boat rides; the best ones are Coffins Patch, Sombrero Reef and Delta Shoal.

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Anett Szaszi

Anett is a certified scuba diver, freediver and an expert in snorkeling with more than 10 years experience. She fell in love with the ocean when she put her head underwater in the Red Sea in 2008. Since then , she is traveling all over the world to discover our waters. Wherever she goes, she takes her mask, fins and underwater camera with her. Visiting mega-cities is not her style but getting lost in tiny coastal villages, capturing the beauty of the sea while snorkeling. She is interested in sustainable traveling and marine conservation. She is hoping to inspire people to protect our oceans by sharing her underwater stories. Find her photos on @anett.szaszi Instagram too!