Anchorage

Great Marsh Island

Shelter: NW, N, NE, SW, S, SE
Seabed: sand
Anchoring: Allowed

Anchorage off Great Marsh Island, near the junction of Sisters Creek and the St Johns River, east of Jacksonville, Florida.

Pontoon

Guide

Approach and anchoring

Great Marsh Island lies where Sisters Creek meets the St Johns River, at the southern end of this stretch of the Atlantic Intracoastal Waterway. Anchor over sand. Tidal current runs strongly through the river mouth, so allow scope and time an arrival near slack water. Sister Creek Docks lie 1 mile to the north.

Practical

No facilities at the island. Sand bottom with good holding. The anchorage is sheltered from a wide arc, from north-west through to south-east. Jim King Park at Sisters Creek Marina, about 1 mile north, has free floating docks with a 72-hour limit, water spigots and restrooms.

Ashore

Jim King Park occupies the site of a former commercial marina bought by the City of Jacksonville in 1997, with a picnic area and a playground. The fishing village of Mayport, with seafood markets and the St Johns River ferry, lies a short run away.

Key facts

Type: Anchorage
Coordinates: 30.38205, -81.46439 (30°22.92'N 81°27.86'W)
Country: United States
Shelter: Sheltered from north-west, north, north-east, south-west, south, south-east winds
Seabed: sand
Anchoring: Allowed
Services: Pontoon
Boaters' rating: 3.0/5
Updated: July 7, 2026