Mooring field

Boot Key Harbor

The cruisers' harbor of the Middle Keys: 226 city moorings in a natural harbor at Marathon – no reservations, and usually full from Thanksgiving to mid-February.

Marathon · Middle KeysLast checked 21 Oct 2026
City moorings
226
Mooring per day
$25 + tax
West entrance
6 ft MLW
Sister Creek
4.2 ft MLW

Depths come from operators, the Coast Pilot, cruiser reports or a seabed model. This is not a nautical chart and does not tell you whether you will get through – use official charts and Local Notices to Mariners.

Overview

Boot Key Harbor at Marathon is the cruisers' harbor of the Middle Keys. The City of Marathon runs 226 moorings here, 211 for boats up to 45 ft and 15 for boats up to 60 ft – measured overall, including bowsprit, davits and dinghy. The town around the harbor is walkable, with groceries, a chandlery and a hospital.

Getting in

The main entrance is from the west, past the remains of the old Boot Key bridge. The city gives 6 ft at mean low water for the entrance and the channel inside; the Coast Pilot reports 7 ft with shoaling on the south side. The bridge's lift span has been removed, and according to The Boat Galley the old 65 ft power line has gone too.

The south entrance through Sister Creek carries only 4.2 ft at mean low water, with rocks awash on the east side of its mouth. From the Gulf side, masted boats cross under the Seven Mile Bridge at Moser Channel, which has 65 ft of clearance; the current there runs 1.4 to 1.8 kn. The radio towers on Boot Key make good landmarks.

How the mooring field works

There are no reservations. Moorings are assigned during office hours only, and only to boats already inside the harbor; arriving after hours, you anchor and call in the morning. When the field is full you join the waiting list in person at the office.

The field is for liveaboards: no wet storage, and a boat left unoccupied for 10 days counts as stored. Discharge is banned outright – through-hulls must be sealed, the pump-out boat comes once a week on your assigned day, and boats are inspected on arrival and at least every three months.

Anchoring

The city's anchorage lies south of the main harbor channel, between Sister Creek and the Boot Key bridge. Anchoring inside the mooring field is not allowed. Cruisers report poor holding near the old bridge, so back down hard. Boats at anchor pay for the dinghy dock: $25 a day, $105 a week or $260 a month, plus tax.

Facilities

  • Showersopen 24/7
  • Laundry$3 per wash or dry
  • Waterfiltered, $0.15/gal
  • Pump-outone free a week
  • Dinghy dockopen 24/7
  • Ice & lockersat the marina

Good to know

  • Fuel: none at the City Marina; several marinas in the west of the harbor sell gas and diesel, and there is a 50-ton travel-lift yard.
  • Dinghies: must be registered and tagged, at most 12 ft long and 6 ft 6 in wide, with a 4–6 ft painter.
  • When it fills: usually around Thanksgiving, and it stays full until at least mid-February.
  • Seagrass: the flats around the harbor are seagrass; damaging it can bring large fines.

Questions sailors ask

Can I reserve a mooring in Boot Key Harbor?

No. The City of Marathon takes no reservations: moorings are assigned during office hours to boats already in the harbor, and when the field is full you join the waiting list in person.

How deep is the entrance?

The city gives 6 ft at mean low water for the west entrance and the harbor channel, and 4.2 ft for Sister Creek on the south side. Depths change – check the current chart.

Can I anchor in Boot Key Harbor?

Yes, in the city's anchorage south of the main channel between Sister Creek and the Boot Key bridge, but not inside the mooring field. The dinghy dock costs $25 a day plus tax, and Monroe County's 90-day rule applies.

Sources & checks

Written by buoya editorial from the sources above. Every figure was checked against its source on 21 Oct 2026. Anything marked “reported” comes from cruiser reports, not from an official source.