A First-Timer's Guide to Cruising the Florida Keys by Boat

Key Largo to Key West runs about 100 nautical miles point to point. Most first-timers should plan 5 to 7 days to do it right, break the run into legs of 20 to 35 nautical miles a day, and budget real time for weather delays because the Keys will make you wait on wind more than once.

I'm not a Florida captain. I run a dive operation on the other coast, in San Diego Bay, and I spend my days under hulls, not on the flybridge. But bottom condition, fouling, and how a boat handles a long coastal run are things I think about constantly, and a lot of that applies no matter which coast you're cruising. This guide is built around the actual geography and logistics of the Keys run, not a highlight reel of pretty water.

Key takeaways

• The Keys use a mile marker (MM) system running from MM 106 near Key Largo down to MM 0 in Key West, and it's the easiest way to navigate and talk to marinas.
• Plan on 5 to 7 days one-way if you want to actually stop and enjoy it, not just transit.
• Fuel docks are spaced roughly every 20 to 30 miles, but top off at every stop anyway.
• April to May and November are the best weather windows, avoiding both summer thunderstorms and winter cold fronts.
• Florida Bay and the backcountry side run 3 to 6 feet deep in many spots, so draft matters more than people expect.

How long does the Key Largo to Key West run actually take?

Running the Overseas Highway corridor by water, you're looking at roughly 100 nautical miles from Key Largo to Key West, whether you take the Atlantic side (Hawk Channel) or thread through the backcountry on the Gulf side. At 8 knots, a trawler-type cruiser covers that distance in about 12 to 13 hours of straight running time. Nobody does it in one shot, and you shouldn't.

Break it into legs. A realistic first-timer itinerary looks like this:

• Day 1: Stage in Key Largo (MM 100-106), provision, check weather.
• Day 2: Key Largo to Islamorada (MM 80-90), about 20 nm.
• Day 3: Islamorada to Marathon (MM 47-50), about 35 nm, overnight at Boot Key Harbor.
• Day 4: Marathon to Bahia Honda / Big Pine Key (MM 33-37), a short hop, good snorkeling day.
• Day 5: Big Pine to Key West (MM 0-5), about 30 nm.
• Days 6-7: Key West, then start your return or arrange haul-out/storage.

That's a full week and it still leaves slack for a weather day, which you will likely need at least once.

What's the best route, Hawk Channel or the backcountry?

Hawk Channel, on the Atlantic side, is the standard route for most cruising boats. It runs parallel to the reef line, has decent depth (generally 7 to 10 feet in the marked channel), and follows the mile marker system closely, which makes navigation and radio communication with marinas straightforward.

The backcountry, on the Gulf/Florida Bay side, is scenic and has less boat traffic, but it's shallow. Depths of 3 to 6 feet are common outside the marked channels, with plenty of spots that go skinnier. If you're running a sailboat with 5 to 6 feet of draft or a deep-V center console loaded down with gear, stick to Hawk Channel unless you know the backcountry or you're running with someone who does.

Either way, get current NOAA charts covering Miami down through Key West before you go, and don't rely on your chartplotter alone. Sandbars shift in the Keys, and printed chart dates matter less than checking recent local notices to mariners.

Where do you anchor and where do you tie up?

Boot Key Harbor, Marathon (MM 48): This is the most popular overnight stop on the whole run. It's a managed mooring field with roughly 200+ mooring balls, dinghy dock access, showers, and a protected anchorage. Rates typically run in the $20 to $30 per night range, but call the harbormaster ahead since availability and pricing shift by season.

Key West: You've got a few options. Garrison Bight has a mooring field close to town. Fleming Key and the anchorage near Christmas Tree Island (Wisteria Island) are common anchoring spots outside the main channel, but check current regulations since anchoring rules in Key West Harbor have tightened over the years.

Islamorada and Key Largo: Mostly marina stops rather than anchorages, since the water off the main channel gets shallow and grassy fast. Book a slip ahead in season (December through April) because marinas fill up.

A few things to keep in mind everywhere in the Keys: the entire chain is a federally designated no discharge zone, so you need a working holding tank and access to pump-out stations. And don't anchor on coral or seagrass. The Florida Keys National Marine Sanctuary has real teeth on this, with mooring buoys placed at popular reef and snorkel sites specifically so boats aren't dropping hooks on live bottom.

When's the right time of year to go?

Hurricane season runs June through November, and while a direct hit is unlikely on any given week, you're rolling the dice on tropical moisture, afternoon thunderstorms, and higher humidity the whole summer. Winter brings its own problem: cold fronts moving through from December to March can push sustained winds of 20 to 30 knots for two or three days at a stretch, which will pin you down in a harbor whether you like it or not.

April, May, and November tend to be the sweet spot. Water temperatures are still comfortable, front activity has usually calmed down, and you're outside the peak of both hurricane season and the busiest snowbird crowds. That said, no window is guaranteed. Check a real forecast source like the National Hurricane Center or NOAA marine forecasts daily once you're underway, not just before you leave the dock.

One more thing from my side of the business: warm Gulf and Atlantic water grows bottom fouling fast, a lot faster than what I deal with in San Diego Bay. If your boat has been sitting for a while before this trip, get the hull, prop, and running gear cleaned before you leave. A fouled prop costs you fuel range and speed over a 100-mile run, and that's the kind of thing you don't want finding out about halfway to Marathon.

FAQ

How long does it take to cruise the Florida Keys by boat? Plan on 5 to 7 days one-way from Key Largo to Key West if you want to actually stop, snorkel, and enjoy the anchorages. The run itself is about 100 nautical miles and can be done faster, but rushing it defeats the purpose.

What's the best time of year to cruise the Keys? April, May, and November generally offer the best balance of calm weather, warm water, and lighter crowds. Summer brings hurricane risk and daily thunderstorms, while winter brings cold fronts with sustained strong wind.

Do you need a deep draft boat for the Keys? Not for the main Hawk Channel route, which generally holds 7 to 10 feet in the marked channel. The Florida Bay backcountry side is a different story, often running 3 to 6 feet deep, so a boat drawing more than 4 to 5 feet should stick to the Atlantic side route.

Where can you anchor for free in the Florida Keys? Options exist near Key West, including the Fleming Key area and the anchorage off Wisteria Island, but rules on Key West anchoring have changed over time so check current regulations before relying on it. Boot Key Harbor in Marathon is a paid mooring field, not free, but it's the most protected and popular overnight stop on the route.

Do I need special charts for the Keys? Yes. Use current NOAA charts covering the Miami to Key West corridor, and check recent local notices to mariners since sandbars and channel depths shift. Don't rely solely on chartplotter data, especially in the backcountry.

Plan the route, then watch the weather

The Keys reward planning more than they reward a rigid schedule. Build in a slack day or two, know your draft limits before you leave the dock, and check weather daily once you're underway. If you're prepping a boat for a long warm-water run like this one and have questions about hull condition or what shape your gear should be in before you go, feel free to reach out. We're happy to talk through it even if your boat's nowhere near San Diego Bay.

SCHEMA NOTES

FAQPage Q&As: 1. Q: How long does it take to cruise the Florida Keys by boat? A: Plan on 5 to 7 days one-way from Key Largo to Key West if you want to actually stop, snorkel, and enjoy the anchorages. The run itself is about 100 nautical miles and can be done faster, but rushing it defeats the purpose. 2. Q: What's the best time of year to cruise the Keys? A: April, May, and November generally offer the best balance of calm weather, warm water, and lighter crowds. Summer brings hurricane risk and daily thunderstorms, while winter brings cold fronts with sustained strong wind. 3. Q: Do you need a deep draft boat for the Keys? A: Not for the main Hawk Channel route, which generally holds 7 to 10 feet in the marked channel. The Florida Bay backcountry side is a different story, often running 3 to 6 feet deep, so a boat drawing more than 4 to 5 feet should stick to the Atlantic side route. 4. Q: Where can you anchor for free in the Florida Keys? A: Options exist near Key West, including the Fleming Key area and the anchorage off Wisteria Island, but rules on Key West anchoring have changed over time so check current regulations before relying on it. Boot Key Harbor in Marathon is a paid mooring field, not free, but it's the most protected and popular overnight stop on the route. 5. Q: Do I need special charts for the Keys? A: Yes. Use current NOAA charts covering the Miami to Key West corridor, and check recent local notices to mariners since sandbars and channel depths shift. Don't rely solely on chartplotter data, especially in the backcountry.

BlogPosting summary: A practical, mile-marker-based itinerary for first-time boaters cruising the Florida Keys from Key Largo to Key West, covering route choice, anchorages, fuel stops, and seasonal weather timing.

Suggested images: - Alt: "Chartplotter showing a boat route through the Florida Keys with mile markers from Key Largo to Key West" - Alt: "Sailboat anchored in Boot Key Harbor mooring field in Marathon, Florida Keys"