Not many hotels in the Florida Keys let you roll out of bed, walk to a dock, and step onto a dive boat — but that’s exactly what you get at Blackfin Resort & Marina.
**Tilden’s Scuba Center** operates right here on our property at Mile Marker 49.5. Their boats depart from the docks behind the shop, which means our guests have the shortest walk to some of the best diving and snorkeling in the Middle Keys. No shuttles, no driving across town. Just grab your gear and go.
## A Full-Service Dive Shop Steps From Your Room
Tilden’s has been serving divers and snorkelers in Marathon since 1990. They’re a full-service operation — PADI, NAUI, and SSI certified — offering everything from beginner courses to advanced wreck diving certifications. Whether you’ve never put your face underwater or you’re a seasoned diver looking to log another site, Tilden’s has a trip for you.
Their daily boat schedule runs two trips: a morning trip from 8:00 AM to noon, and an afternoon trip from 1:00 PM to 5:00 PM. Equipment rentals are available if you’d rather not travel with your own gear, and they carry a full retail selection of dive and snorkel equipment in the shop.
## What You Can Do
**Snorkeling** — Perfect for families and first-timers. Tilden’s takes snorkelers out to the same stunning reefs the divers visit, including Sombrero Reef, one of the most popular snorkeling destinations in the entire Florida Keys. The shallow areas of the reef sit just a few feet below the surface, so you’ll get an incredible view without needing any certification or experience.
**Scuba Diving** — Marathon sits along the third-largest barrier reef system in the world, and Tilden’s has access to over 30 different dive sites. Classes start daily and are kept intentionally small for a more personal experience. If you’ve always wanted to try scuba, their one-day resort course gets you breathing underwater with no prior experience needed.
**SNUBA** — Something in between? SNUBA lets you breathe underwater like a scuba diver but without the full certification. It’s available for ages 8 and up, making it a great option for families with kids who want more than snorkeling but aren’t ready for a full scuba course.
**Spearfishing and Lobstering** — For the more adventurous, Tilden’s offers spearfishing and lobstering trips (in season) on the reefs surrounding Marathon.
## Sombrero Reef: World-Class Snorkeling and Diving Minutes Away
One of the top sites you’ll visit with Tilden’s is Sombrero Reef, a protected Sanctuary Preservation Area located a few miles offshore from Marathon. The reef covers over 200 acres and features a classic spur-and-groove formation — ridges of coral separated by sandy channels — that creates an incredibly diverse underwater landscape.
The reef is marked by the historic Sombrero Key Lighthouse, built in 1858 and standing 142 feet tall. Below the surface, the water ranges from just a couple of feet deep on the shallow coral tops to around 30 feet in the grooves, making it accessible for snorkelers and divers alike.
What can you expect to see? Parrotfish, angelfish, yellowtail snapper, barracuda, hogfish, nurse sharks, moray eels, sea turtles, and spotted eagle rays are all common sightings. The coral itself — including elkhorn, brain, star, and sea fans — is part of the only living coral barrier reef in the continental United States.
## The Thunderbolt: Marathon’s Signature Wreck Dive
If you hold an Advanced Open Water certification, don’t miss the Thunderbolt. This 188-foot former World War II cable-laying ship was intentionally sunk in 1986 as an artificial reef and now sits upright and intact in about 120 feet of water, roughly five miles offshore from Marathon.
After nearly four decades on the ocean floor, the Thunderbolt is encrusted with colorful soft corals and sponges. Goliath groupers weighing hundreds of pounds patrol the wreck year-round, along with large schools of amberjack and, during summer, migrating tarpon. The ship’s giant cable reel on the bow is one of the most photographed features on any wreck in the Keys.
Tilden’s schedules Thunderbolt dives on request — just let them know when you’re visiting and they’ll work to get you on the wreck. A minimum of three divers is required for the trip to go.
## Stay at Blackfin, Dive With Tilden’s
Having an on-site dive shop is one of the things that makes Blackfin Resort & Marina unique among Marathon accommodations. You can combine a comfortable waterfront stay with world-class diving and snorkeling without needing to coordinate transportation or logistics.
Here’s what a typical dive day looks like for our guests:
1. Wake up and grab coffee in your room
2. Walk over to Tilden’s to check in and sign the manifest
3. Head to the dock right behind the shop
4. Spend the morning exploring Sombrero Reef or diving the Thunderbolt
5. Come back to the resort, rinse your gear at the dock, and relax by the pool or on our private beach
6. Head out again for the afternoon trip if you’re up for more
Ready to plan your dive trip? Contact Tilden’s Scuba Center at **(305) 743-7255** or visit [tildensscubacenter.com](https://www.tildensscubacenter.com/) to learn more about trips and certifications. Then [book your stay at Blackfin Resort & Marina](https://S006434.officialbookings.com) and make the most of your time in the Florida Keys.