Florida Keys Atoll · Marquesas Keys

Marquesas Keys — the only natural atoll in the Western Hemisphere.

A ring of uninhabited mangrove islands enclosing a shallow lagoon, 25 miles west of Key West. Frigate birds overhead, sea turtles cruising the seagrass, water clear enough to see baitfish from the bow. The destination you can't reach without a captain.

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USCG-licensed captain Private boat — your group only From $2,605

Why the Marquesas is unlike any other Keys destination

Three things you only get here.

The Marquesas isn't a sandbar — it's an atoll. The unique geology and 25-mile distance from Key West deliver a destination that doesn't exist anywhere else in the continental U.S.

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The only natural atoll

A ring of islands enclosing a shallow lagoon. There's no other atoll in the Western Hemisphere. Geologists debate exactly how it formed (popular theory: a meteorite). The result is a destination unlike any sandbar in the Keys.

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Sea turtles, frigates, dolphins

Wildlife density is high — the atoll is inside the Key West National Wildlife Refuge. Frigate birds wheel overhead, sea turtles cruise the seagrass beds inside the lagoon, occasional bottlenose dolphins move through the inlets.

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World-class snorkel

The inside of the atoll has shallow patch reefs and seagrass meadows in clear water. Outside the atoll, channel-edge reefs hold larger fish. On calm days the visibility inside the lagoon is among the best in the Florida Keys.

A full-day expedition

What a Marquesas day actually looks like.

From our Perry Hotel & Marina dock, the run to the Marquesas is about two hours westward across open water. Captain Dustin watches the forecast and won't run on rough days. On a calm morning the trip itself is part of the experience — flying fish, frigate birds overhead as you approach the atoll, the ring of mangrove islands rising out of the water on the horizon.

Anchoring inside.

The atoll has several inlets; we anchor inside the protected lagoon. The water is shallow and sandy — you can step off the swim platform into knee-deep clear water. Pick a side based on wind. The inside of the atoll is wind-protected almost regardless of direction.

What you do on site.

Snorkel the inside patch reefs and seagrass beds. Swim to the nearest mangrove edge and explore. Birding — bring binoculars. Some groups bring a paddleboard and circle the inside of the lagoon. Lunch on the boat under the bimini. Most groups spend 3-4 hours inside the atoll before turning home.

Pair with Boca Grande.

Boca Grande Key sits 13 miles east of the Marquesas, on the way back to Key West. Many full-day Marquesas charters add a Boca Grande stop on the return for the empty beach. See our Boca Grande page for details.

The wind condition matters more than usual.

The 25-mile run is across open water with no shelter on the way. South or southwest wind makes the trip rough. Calm conditions make it smooth. Captain Dustin checks forecast 48 hours out and we'll proactively reach out if conditions look unsafe — reschedule is always an option.

How Six Fins gets you to the Marquesas

Two formats, same destination.

Marquesas charters are full-day only. Both options launch from our Perry Hotel & Marina dock on Stock Island. Private-charter only.

Two destinations

Marquesas + Boca Grande

Adds a Boca Grande Key stop on the return. Empty beach plus atoll lagoon in the same day. About 10 hours total. From $3,065.

See Boca Grande →

Marquesas Keys FAQ

Marquesas Keys questions, answered.

Are the Marquesas Keys really a sandbar?

Not exactly. The Marquesas are an atoll: a ring of uninhabited mangrove islands around a shallow lagoon about 25 miles west of Key West.

This page belongs in the sandbar family because guests anchor, swim, snorkel, and explore shallow clear water, but the Marquesas experience is bigger and more remote than a simple sandbar stop.

How far are the Marquesas from Key West?

The Marquesas Keys are about 25 miles west of Key West. The run is usually about two hours each way depending on wind, sea state, route, and cruising conditions.

That distance makes the Marquesas a full-day private charter, not a quick add-on to a short sandbar trip.

Why is the Marquesas trip special?

The Marquesas feel different because of the atoll shape, distance from Key West, protected lagoon, shallow seagrass, mangrove islands, birds, sea turtles, and open-water run.

It is the destination for guests who want something beyond the standard Key West sandbar circuit and are comfortable spending the day on the water.

Can we go on the islands?

Landing is limited and depends on refuge rules, bird nesting closures, shoreline conditions, and captain judgment. Many parts are mangrove or protected habitat, not walkable beach.

The main experience is the lagoon, shallow water, snorkeling, wildlife viewing, and anchoring inside the atoll, not walking miles of dry beach.

Can we pair Marquesas with Boca Grande?

Yes. Boca Grande sits on the return route east of the Marquesas and is the natural pairing for a longer day.

The 10-hour Marquesas + Boca Grande format starts at $3,065 and is the right choice if your group wants both the atoll lagoon and Boca Grande's empty beach feeling.

Is the Marquesas trip weather-dependent?

Yes. The 25-mile run west crosses open water, so wind and sea state matter more than they do on a protected backcountry sandbar day.

If Six Fins or the captain determines the trip is unsafe or unsuitable, guests may be rescheduled or refunded according to the applicable booking policy. The captain will not force the Marquesas in marginal offshore conditions.

What does the Marquesas charter cost?

The Marquesas is a full-day private charter starting at $2,605 for 8 hours. The 10-hour Marquesas + Boca Grande version starts at $3,065.

Pricing is per boat, not per person. Up to 6 guests is standard, with 8 by arrangement where the charter setup allows.

Is Marquesas good for kids or first-time boaters?

It can be, but it is a long day and a longer open-water run. Guests should be comfortable spending most of the day on a boat.

Families with younger kids or anyone concerned about motion may prefer Woman Key, Man Key, Sand Key, Jewfish Basin, or Snipes Keys for an easier first private charter.

Also explore

Ready for the atoll?

Send us your date and group size. We watch the weather and pick a calm day. If your flexibility window allows it, we'll match conditions to your trip.

Pick the sandbars you’d like to visit.

Your captain matches destinations to the wind, tide, and conditions of your booked day. Selections become a request the captain will confirm before your trip.

Pick at least one sandbar to see your recommended charter.
Or call (305) 906-2880 to plan with the team

Or email info@sixfinscharter.com with your date and group size.