East Sister Rock Island, a 6.44-acre private island situated a quarter-mile off Marathon in the Florida Keys, has been listed for sale at $16 million. The property, which includes approximately 5.8 acres of surrounding seabed, offers a secluded tropical retreat with a range of amenities.
The island features a three-bedroom, two-bathroom main residence and a detached guest house, providing over 5,000 square feet of combined living and entertaining space. A 12-foot-wide wraparound veranda offers panoramic ocean views, complemented by a waterfront pool and spa.
For accessibility and convenience, the property is equipped with a private helipad and a 100-foot deep-water dock suitable for boats. The island also boasts a comprehensive self-sufficiency system, including solar and wind power, battery storage, a backup generator, a desalination system, and a large freshwater cistern.
The sale includes a mainland property at 99 E Ocean Drive, offering additional private dock space in Marathon. The listing agent is Vladimir Rochebrun of The Chad Carroll Group at Compass.
This is not the first time the island has been on the market. It was previously listed for $11.7 million in February 2021, taken off the market in 2022, and has now returned at a higher price point.
The asking price of $16 million is more than five times the average single-family home price in the 33050 ZIP code, which is approximately $2.91 million. Annual property taxes for East Sister Rock Island are reported to be about $25,481.