Marked by the historic Sombrero Key Lighthouse, this site lies approximately four to five nautical miles offshore from Vaca Key and the city of Marathon. For us at Captain Hook’s, it’s one of our longer boat rides when compared to the other sites we visit, but it’s well worth it! Sombrero Reef is definitely one of my favorite spots to see. 

This guide aims to provide everything you need to know about Sombrero Reef to have the best time snorkeling and diving. 

Why Choose Sombrero Reef? Unique Features & Underwater Appeal

Sombrero Reef’s allure stems from a combination of factors that make it a standout destination in the Middle Keys. Its geological structure, accessibility, marine life potential, and iconic landmark contribute to its enduring popularity.

Spur and Groove Formation

The reef itself showcases a classic “spur-and-groove” formation. This natural architecture consists of coral ridges (spurs) extending up towards the surface, separated by sandy channels (grooves). Some people also call this “finger coral”. This topography creates a diverse underwater landscape with depths varying significantly, ranging from just a few feet near the lighthouse structure to around 30 feet in the deeper channels. Such variation caters well to different preferences and skill levels, allowing snorkelers to explore shallow areas while divers can investigate the deeper grooves and formations. It’s without a doubt one of the best sites we visit thanks to the abundance of fish, the different structure, the varying depths and more. 

Plenty to See for Divers and Snorkelers of All Levels

From first-time snorkelers to seasoned divers, the site offers plenty to see for everyone. It’s one of the best locations for handling mixed groups, ensuring that varying abilities, divers and snorkelers can all enjoy the excursion together on the same boat. 

While the coral landscape has faced significant challenges in recent years, Sombrero Reef still supports a rich biodiversity. Its status as a Sanctuary Preservation Area (SPA), where fishing and lobstering are strictly prohibited, contributes to healthier and more abundant fish life compared to unprotected areas. 

The One and Only Sombrero Key Lighthouse

Dominating the seascape is the unique Sombrero Key Lighthouse. This 142-foot tall, octagonal, cast-iron tower stands on iron pilings driven into the reef. Completed in 1858 under the supervision of George Meade (later famous for the Battle of Gettysburg) [2], it served as a crucial navigational aid until its deactivation in 2015.[1] Exploring right below the lighthouse is tough to do with shallow depths and wave action, but the lighthouse still provides one of the more well known pictures in all of the Keys. 

The combination of these elements creates a compelling experience for visitors:

• The varied and accessible underwater terrain
• The abundance of diverse fish sightings fostered by its protected status
• The unique visual appeal of the historic lighthouse

Planning Your Sombrero Reef Excursion: Getting There & Tour Options

It is crucial to understand that Sombrero Reef is not accessible by swimming from land. It is several miles offshore so you’ll need a boat. It’s sometimes confused with Sombrero Beach, a popular spot in Marathon. The beach is entirely separate from the reef.

Option 1: Guided Snorkel/Dive Tours (Most Common & Recommended)

For the vast majority of visitors, particularly first-timers or those without extensive boating experience in the Keys, joining a guided tour is the most practical and often the safest method. 

We offer scuba diving and snorkeling trips twice per day. Our tours provide all necessary snorkeling gear (mask, snorkel, fins), safety supervision from experienced captains and mates, and local knowledge to navigate to the best spots within the reef system. For more information about pricing, what to bring, when we depart, etc, visit our snorkeling and dive trip links below:

• Diving in Marathon
• Snorkel Trips in Marathon

Option 2: Private Boat / Rental

Visitors with boating experience or those renting a boat can travel to Sombrero Reef on your own. The reef features a system of mooring buoys located on the south side of the lighthouse, designed for vessels to tie off to. 

Some important notes:

• Anchoring directly on the reef is strictly prohibited within the Sanctuary Preservation Area to prevent damage to the fragile ecosystem.
• The approximate coordinates for the reef are 24°37′36″N 81°06′39″W.
• A dive flag must be prominently displayed when diving or snorkeling.
• Not adhering to the SPA guidelines can result in costly fines.

What Will You See at Sombrero Reef?

Once at the reef, you’ll finally get to experience the beauty of this reef. The spur-and-groove formations create an awesome environment. Truly one of my favorite places to see! 

Snorkelers can glide over the shallower tops of the coral spurs, often just several feet below the surface in some areas. Divers can explore the sandy grooves that can reach depths of 20 to 30 feet. There are plenty of interesting coral formations, like mini-canyons and, historically, large coral structures like the notable elkhorn arch. Again, just be very careful of damaging the reef. 

The main draw for many visitors today are the different kinds of fish. Divers and snorkelers can expect to see many of the following:

• Parrotfish: Stoplight, Queen, Rainbow, and Midnight Parrotfish are frequently seen grazing on algae.
• Angelfish: Queen, French, and Gray Angelfish add splashes of color.
• Snapper: Schools of Yellowtail Snapper are everywhere, along with Gray Snapper.
• Surgeonfish: Including the popular Blue Tang (aka Dory)
• Grunts & Chubs: Often seen in large schools.
• Other Reef Fish: Damselfish, wrasse, butterflyfish, sergeant majors, and more.
• Larger Inhabitants: Sightings of Southern Stingrays, Eagle Rays, Nurse Sharks (generally docile bottom-dwellers) and Turtles. Barracuda are also common inhabitants.

While specific sightings are never guaranteed in the wild, the protected nature of Sombrero Reef significantly increases the chances of encountering all sorts of sea life.

The Captain’s Tips for Diving or Snorkeling at Sombrero Reef

Here are some tips from the crew at Captain Hook’s to get the best experience at Sombrero Reef:

1. Check the Weather: Wind and wave conditions significantly impact visibility and comfort. Calm days offer the best snorkeling. Check marine forecasts before booking or heading out.
2. Wear Reef-Safe Sunscreen: Standard sunscreens contain chemicals harmful to coral. Opt for mineral-based sunscreens (zinc oxide, titanium dioxide) or wear protective clothing like rash guards.
3. Do Not Touch or Stand on Coral: Coral is a living animal, extremely fragile, and easily damaged or killed by touch. Maintain buoyancy and keep fins away from the reef structure. Standing on coral is illegal and harmful.
4. Never Feed the Fish: Feeding marine life disrupts natural behaviors and can be harmful to their health.
5. Use Mooring Buoys, Do Not Anchor: If on a private vessel, always use the provided mooring buoys. Anchoring on coral or seagrass is prohibited and damaging.
6. Bring Necessary Gear: we offer quality rental gear, but consider bringing your own well-fitting mask if you have one. A GoPro or underwater camera is popular for capturing memories. Consider Dramamine if prone to seasickness, especially for longer boat rides.
7. Stay Hydrated: Bring water, especially on private trips. We provide water and coolers on our boats.
8. Listen to Your Captain/Crew: On guided tours, pay attention to your captain and crew. They know how to keep you safe, and they probably have some great tips to see more of what you want. 
9. Be Aware of Currents: Even on calm days, currents can be present around the reef. It’s easy to get pulled away from the boat. Always be aware of which way the current is pushing you. 

Following these guidelines helps protect the reef for future generations and ensures a safer, more enjoyable trip for everyone.

Other Popular Reefs Close to Sombrero Reef

Besides the renowned Sombrero Reef, boaters departing from Marathon can explore several other excellent reef sites nearby:

1. Coffins Patch: Located a few miles east of Sombrero Reef, Coffins Patch reef consists of a series of patch reefs rather than a continuous barrier line. Known for often having high concentrations of fish life and generally shallower depths than the outer reef line, Coffins Patch is very popular for snorkeling and offers numerous mooring buoys.
2. Delta Shoal: Situated west/southwest of Sombrero Reef, Delta Shoal provides another worthwhile destination. It features some nice coral formations, diverse species of fish, and a good mix of shallow and deep areas. 

Common Questions about Sombrero Reef

Can you kayak to Sombrero Reef?

Kayaking to Sombrero Reef is strongly discouraged and generally considered unsafe. The reef sits approximately 7-8 nautical miles offshore from Marathon. This significant distance, combined with exposure to potentially strong currents, unpredictable weather, wind, waves, and boat traffic, makes kayaking extremely hazardous and strenuous, even for very experienced paddlers.

What is the current condition of the coral at Sombrero Reef?

Sombrero Reef’s coral has been impacted by recent environmental stressors. Reports and visitor feedback discuss some coral bleaching and mortality. We constantly working through our Coral Program to help mitigate these effects as much as possible. With that said,Sombrero Reef remains one of the best places to snorkel in Marathon, and all of the Florida Keys. 

Why is the coral damaged?

Coral damage occurs due to several factors, including:

• Coral Bleaching: Caused by record-high water temperatures.
• Storm Damage: Lingering effects from events like Hurricane Irma (2017).
• Disease: The ongoing Stony Coral Tissue Loss Disease (SCTLD) pandemic has affected reefs throughout the Keys.

Is Sombrero Reef good for beginner snorkelers or families with children?

Yes, Sombrero Reef is generally good for beginners and families, especially on calm days. It features shallow areas (around 5-15 feet) suitable for snorkeling. However, since it’s an open-ocean reef, always check conditions first; tours are often recommended for novices.

How do I get to Sombrero Reef? Can I swim there from shore?

Sombrero Reef is located approximately 8 nautical miles offshore from Marathon in the Florida Keys. Because of this distance and open water conditions, it is not possible to swim to the reef from shore. Access is exclusively by boat. You can either take your own private vessel or join one of the many licensed snorkeling or diving charter boats operating out of Marathon.

Are You Ready to Visit Sombrero Reef?

Now that you know more about the stunning underwater world waiting at Sombrero Reef, it’s time to plan your adventure! For expertly guided snorkeling tours or diving trips departing directly from Marathon, let Captain Hook’s Marina and Dive Center take you there. We provide everything you need for a safe and memorable excursion to Sombrero Reef and other nearby locations.

Ready to book or want more details? Click here to view all of our available services and book your trip. 

The post Diving & Snorkeling at Sombrero Reef in Marathon FL appeared first on Captain Hook's Marina and Dive Center.

With calm, clear water and vibrant marine life, Coffins Patch offers an accessible and family-friendly reef experience. Its shallow depths and plethora of sea creatures make it great for snorkelers and novice divers looking to explore a coral reef up close​ and personal!

This guide covers everything you need to know for a Coffins Patch snorkel or dive trip – from location and conditions to wildlife sightings, local insights, and tips to make the most of your snorkel or dive trip.

Coffins Patch Reef Overview

Where is Coffins Patch? Location & Protected Status

Coffins Patch lies ~3.5–4.5 miles offshore from Marathon (Vaca Key/Key Colony area) in the Florida Keys​. This cluster of patch reefs spans about 248 acres within the Florida Keys National Marine Sanctuary. Coffins Patch is designated as a Sanctuary Preservation Area (SPA). This means the reef is federally protected. No fishing, spearfishing, or collecting of marine life is allowed here​.

Latitude: 24° 41′ 4.19″ N
Longitude: -80° 57′ 59.99″ W

Reef Features & Underwater Landscape

Coffins Patch isn’t a single reef. It’s a collection of about six distinct patch reefs that all have their unique quirks. Notable sites within Coffins Patch include “The Stake” (named after the angled steel post visible above the water) and “The Aquarium”​. These are two popular locations for snorkel trips in the Marathon.

Depth and Terrain

The area is very shallow with depths ranging from roughly 5 to 25 feet across the patches​.
Some coral heads even rise near the surface. The reef features sandy bottoms dotted with hard corals. We often see big boulder and brain corals and lush soft corals like sea fans and gorgonians waving in the current​. These soft corals and sea fans create vibrant scenery for snorkelers.

Larger coral formations top out around 5–10 feet below the surface, while deeper sand channels may reach ~20–25 feet on the edges​.

This topography is perfect for snorkelers (who can easily see the reef from the surface) and also allows adventurous free-divers or novice scuba divers to explore nooks and crannies on the reef floor.

Visibility & Conditions

Thanks to its offshore location near the Atlantic reef crest, Coffins Patch often enjoys excellent water clarity. On calm days, visibility can easily be 50+ feet, revealing the full beauty of the coral and fish below. Currents are typically pretty calm here. That’s why this is also one of the best places to dive in all of the Florida Keys.

The shallow depth also means more sunlight which really helps snorkelers see a colorful environment below. With that said, conditions always vary with weather – wind or storms can stir up waves and reduce visibility. Pick a calm day for the best experience.

What Kind of Fish Will You See at Coffins Patch?

Tropical Fish

Coffins Patch has no shortage of colorful tropical fish. Snorkelers commonly encounter schools of blue tangs, sergeant majors, angelfish, parrotfish, butterflyfish, and many others swimming around the coral below.

On a single outing you might easily spot 20+ fish species ranging from small damselfish to larger reef fish. Brightly colored queen angelfish, stripy yellow sergeant majors, and iridescent blue parrotfish are just a few favorites that add splashes of color to the your trip. 

Larger Sea Creatures

The reef’s healthy habitat attracts plenty of bigger marine life as well.

• Keep an eye out for stingrays gliding over the sand and spiny lobsters hiding under ledges​.
• We commonly see Grouper, snapper and barracudas throughout this reef as well.
• You might even see a curious moray eel peeking from a crevice​.
• Nurse sharks also frequent Coffins Patch. These lazy sharks often nap on the bottom and may peacefully swim by snorkelers (they are not aggressive to humans so don’t worry!)​.
• Lucky visitors have even sighted sea turtles and the occasional eagle ray passing through.

Coral and Plant Life

• Coffins Patch has a mix of hard coral like brain, star, and boulder corals.
• You’ll also see plenty of soft coral like sea fans, sea whips, and rod corals that sway with the water.
• You’ll also notice various sponges (tube and vase sponges in orange, purple, etc.) and patches of seagrass or algae on the substrate.

Historically, this area was known for stands of rare pillar coral as well​ though many corals have suffered recent bleaching (more on that in a later section).

Snorkeling at Coffins Patch Reef – What to Expect

Coffins Patch is often touted as a perfect snorkel site for beginners and families because of its shallow depth and typically gentle conditions​. Much of the reef lies just a few feet below you, so you can float on the surface and see plenty without diving down. The shallow areas (5–10 ft) allow even novice swimmers to feel comfortable while observing fish and corals with a problem.

While snorkeling, you’ll drift over beautiful coral heads. There will be plenty of fish darting in and out of the coral. Freediving down a few feet can reward you with a closer look. Even at only 10–15 feet deep, you can inspect the base of coral heads where lobsters or eels might hide.

The water is typically warm (in the 80°F range in summer), and you can comfortably spend an hour or more exploring the patch reefs. Many snorkelers are surprised by how much there is to see even in such shallow water.

Gear and Safety – What Do You Need to Bring?

Standard snorkel gear (mask, snorkel, fins) is sufficient. Bring a dive flag if snorkeling from a private boat. Florida law requires a “diver down” flag when people are in the water. Wearing a snorkel vest is a good idea for added buoyancy if you’re not an experienced swimmer.

Bonus Tip: Use reef-safe sunscreen or wear a rash guard to protect yourself from the sun – and to protect the reef. Chemicals from the sunscreen wash off your body and contribute to coral bleaching. Also, never touch or stand on the coral. You can easily damage coral

Scuba Diving at Coffins Patch

Certified divers can also enjoy Coffins Patch, though the shallow max depth (~20–25 ft) means this is more of a relaxed, easy dive than a deep exploration. It’s a great dive site for beginner divers or training dives.

It’s also an awesome place to go if you’re into underwater photography. The protected reefs and shallow depths really look awesome with all of their color. You can do long bottom times here due to the shallow depth and still have air to spare.

There is usually minimal current at Coffins Patch, making it easy to stay with your group and near the boat. Visibility is generally very good, though divers will stir up sand if you kick too close to the bottom. Overall, divers will find Coffins Patch a low-stress, high-reward site for viewing the Keys marina life.

How to Get to Coffins Patch

Coffins Patch is only accessible by boat. It’s a few miles offshore, so you will need to either go with a snorkel tour company or have access to a private boat. Kayaking or paddleboarding that far offshore is not advisable for most people. Strong winds, currents, distance and boats can make it dangerous​.

Commercial Tours to Coffins Patch

The easiest option is to book a commercial snorkel tour out of Marathon or Duck Key. Numerous tour operators run half-day trips to Coffins Patch. These tours typically provide all gear, boat transport, and a guide, making it stress-free. You’ll visit 2–3 dive sites for about an hour each​.

How to Get to Coffins Patch on Your Own Boat

If you have your own boat or a rental, you can navigate to Coffins Patch yourself. Coordinates are marked on nautical charts and many GPS units. There are usually multiple white mooring balls on the site to anchor your boat. Do not anchor on the reef under any circumstances​. Anchoring on living coral is illegal in the SPA. Tie up to a mooring buoy and double-check it’s secure. Display a dive flag when people are in the water. If you’re not very experienced with boating in the Keys, consider the tour option. It’s easy to accidentally damage seagrass beds or coral heads and incur hefty fines in protected zones​. Going with a guided trip your first time can show you the ropes.

Best Time to Visit

It’s pretty simple. Calm weather = Best snorkeling. The weather and sea conditions will greatly impact your Coffins Patch experience. The best time to go is on days with low wind and calm seas when the water is flat and clear. Generally, the late spring through summer months offer warm water and many calm days. In winter, cold fronts can bring strong winds that make the ocean choppy (and can cancel boat trips). November – March tends to be windier and can have rougher conditions​, while April – October usually has more favorable snorkeling weather (aside from storm events).

What is the Best Time of Day to Snorkel or Dive?

Morning trips are often ideal. Winds are often lighter in early mornings, but this varies pretty widely. Many tour operators run trips around 8:30 AM and again around 1 PM. If you go in the middle of the day, be mindful of the sun’s intensity and reapply reef-safe sunscreen or wear UV protective clothing.

Is Coffins Patch Crowded?

Coffins Patch sees less crowding than the famous Sombrero Reef, but it’s still a popular spot. On a perfect-weather day, you might find a handful of tour boats and private boats moored there. To avoid any crowds, try going on a weekday rather than weekends, or earlier in the morning. That said, even when other boats are present, the area is spread out over multiple patch reefs. It rarely feels overly crowded in the water and there is plenty to see!

Top Tips for Snorkeling & Diving at Coffins Patch

• Use the Mooring Buoys: Always hook onto a mooring buoy when one is available at the reef​.
• Mind the Regulations: Remember that all fishing and collecting is prohibited at Coffins Patch​.
• Reef Etiquette: Practice good reef etiquette to keep Coffins Patch healthy. Do not touch, stand on, or kick the corals​.
• Let the fish come to you: The marine life in Coffins Patch knows they’re in a safe place. Take moments to just be still and watch as the fish come close to you (especially diving). 

How Does Coffins Patch Compare to Other Reefs?

Coffins Patch vs. Sombrero Reef

These are the two most popular snorkel spots in Marathon. They’re also great beginner dive sites. Sombrero Reef (marked by its lighthouse) has impressive “finger” coral formations in 15–30+ ft of water. They’re really an awesome site and one of the more unique experiences in Marathon. ​

Coffins Patch is shallower, more sheltered, and often less crowded. Many of the snorkelers on our snorkel and dive trips appreciate​ this. Coffins Patch’s coral is spread over patch reefs with lots of fish in the 5–15 ft range. If you have time, do both. If you prefer calmer conditions and an easier snorkel experience, I’d go with Coffins Patch. If you’re diving, I’d go with Sombrero.

Coffins Patch vs. Alligator Reef (Islamorada)

Alligator Reef (about 50 miles northeast) is another well known shallow reef in the Upper Keys. It’s similar in depth (5–20 ft) and marine life to Coffins Patch. Alligator is a larger reef structure. One advantage of Coffins Patch is that it’s closer for those staying in Marathon. Both are SPAs and offer great snorkeling. If your Keys trip spans multiple regions, they’re both worth visiting.

Other Sites Nearby

You might also hear about Hawk’s Cay Sandbar or Grassy Key Sandbar. These are popular for a post-snorkel swim in the beautiful turquoise water. Some tours combine a Coffins Patch snorkel with a stop at a calm sandbar for a fun dual excursion​.

Wrapping Up: Coffins Patch is an Awesome Beginner Dive Site & Snorkel Location

Coffins Patch remains a must-visit spot for snorkelers and divers exploring the Middle Keys. Its combination of shallow, clear water and thriving marine life is a no-brainer selection.

Whether you’re a first-time snorkeler or a seasoned diver, this reef will have something to see! For more information about diving and snorkeling in the Florida Keys, or to book a trip, you can reach out to Capt. Hook’s Marina and Dive Center. We offer daily snorkeling and scuba dive trips in Marathon.

Click here to book any of our watersports activities online quickly and easily! 

The post The Divers and Snorkelers Guide to Coffins Patch in Marathon FL appeared first on Captain Hook's Marina and Dive Center.