The stretch of the Florida Keys from Tavernier through Marathon encompasses some of the finest anchorage territory in the Americas. Protected basins, uninhabited mangrove islands, crystal-clear sandbars, and deep-water channels — all within a day’s cruise of Islamorada. This guide covers the seven best anchorages in this stretch, with depth ranges, access notes, and honest sunset ratings.

1. Shell Key (Florida Bay Side) ⭐⭐⭐⭐⭐

Depth: 3–7 feet | Bottom: Sand and grass | Sunset: Spectacular

Shell Key is the anchorage that reminds you why people drive from all over the Southeast to spend a week in the Keys. Located in Florida Bay northwest of Upper Matecumbe Key, the sandbars here glow turquoise at low tide and attract everything from weekend warriors in center consoles to liveaboard cruisers anchoring for days. The sunsets over the bay from here are world-class. There is no development, no noise, and no reason to leave until you absolutely must. Carry a dinghy — the best spots require wading or tendering to the bars.

2. Little Basin (Windley Key) ⭐⭐⭐⭐⭐

Depth: 5–12 feet | Bottom: Sand | Sunset: Good (sheltered)

Little Basin is a protected tidal basin on the oceanside of Windley Key — ideal for overnighting because it’s sheltered from prevailing southeast winds and has excellent holding ground. It’s accessible via a marked channel from the Atlantic side. During tarpon season, the channel mouth at Little Basin produces excellent tarpon action at night, making this anchorage popular with anglers who want to fish late and sleep under the stars. Depths of 8–12 feet accommodate most cruising boats.

3. Butternut Key (Bayside) ⭐⭐⭐⭐

Depth: 4–9 feet | Bottom: Grass and sand | Sunset: Outstanding

Butternut Key is an uninhabited mangrove island in Florida Bay accessible only by boat — which means the fishing is better and the crowds are smaller. The protected bay on the western side provides calm water and a dramatic sunset backdrop over the bay. Bonefish actively feed on the flats surrounding this island, making it a combination anchorage and fishing destination. Depths can be tricky — use a chart plotter and approach at high tide if you’re drawing more than 4 feet.

4. Long Key Bight ⭐⭐⭐⭐

Depth: 6–14 feet | Bottom: Sand | Sunset: Very good (bay exposure)

Long Key Bight, along the bayside of Long Key State Park, is one of the most accessible anchorages for boats crossing from the Islamorada area south toward Marathon. The park’s mangrove shoreline provides a beautiful backdrop, and snorkeling on the nearby patch reefs is excellent. This is a good overnight waypoint if you’re doing a Keys cruise — anchor in 8–12 feet, enjoy sunset, and continue south the next day.

5. Fiesta Key (Bayside Anchorage) ⭐⭐⭐

Depth: 5–10 feet | Bottom: Grass | Sunset: Good

Fiesta Key offers a more accessible anchorage for boaters who want a night stop with easy access to services — the KOA campground on Fiesta Key has fuel, a camp store, and facilities. Not the most remote or beautiful anchorage on this list, but practical for a fuel stop or overnight before pushing on. Holding is adequate in grassy bottom and the approach is straightforward.

6. Duck Key Basin ⭐⭐⭐⭐

Depth: 6–20 feet | Bottom: Sand | Sunset: Very good

Duck Key is a residential island with a marina, but the surrounding basins and channels provide excellent anchorage for cruising boats. The approach from the Atlantic side via Hawk’s Channel is simple and deep. Hawks Cay Resort’s full-service marina is nearby for fuel, water, and amenities if needed. The channel basin here is one of the more reliable anchorages in this stretch for larger vessels (drafts to 5.5 feet).

7. Boot Key Harbor (Marathon) ⭐⭐⭐⭐⭐

Depth: 8–15 feet | Bottom: Mud/sand | Sunset: Excellent from anchorage

Boot Key Harbor in Marathon is the single largest anchorage field in the Florida Keys — hundreds of moorings and plenty of anchor space, protected by mangroves on all sides. The Marathon City Marina and Dockside Watersports provide fuel, water, repairs, and provisioning. This is the terminal stop for Keys cruisers heading south and the major waypoint for those crossing to the Bahamas. It’s a full-service cruising destination, not a remote hideaway, but the convenience and scale make it essential for any Keys itinerary.

Boating Tips for the Islamorada to Marathon Run

• Run Hawk’s Channel (Atlantic side) for a deep, marked route — minimum 7 feet at mean low water
• Florida Bay is shallower and requires chart plotter navigation — 4 feet draft max on much of the route
• The Ocean-to-Bay channels (Snake Creek, Channel 5, Long Key Bridge) are all navigable and useful shortcuts
• Manatee zones throughout the area — observe idle-speed zones religiously
• Call ahead to marinas during peak season (March–June) — dockage fills fast

See our complete Islamorada boating guide for marina listings, fuel docks, and boat rental resources, and our fishing guide for what to target at each of these anchorage locations.

FAQ: Anchoring in the Florida Keys