A private 6.44-acre island located a quarter-mile off Marathon in the Florida Keys, known as East Sister Rock Island, has been listed for $16 million. The property, marketed as a rare opportunity for a secluded tropical escape, includes a main residence, guest quarters, a pool, a private helipad, and a 100-foot deep-water dock.
The island is surrounded by turquoise waters and comes with approximately 5.8 acres of seabed, offering opportunities for snorkeling, fishing, kayaking, and paddleboarding. The main residence features three bedrooms and two bathrooms, complemented by a detached guest house. Together, the structures provide over 5,000 square feet of living and entertaining space, according to the listing. A wraparound veranda offers panoramic ocean views, alongside a waterfront pool and spa.
To ensure functionality independent of the mainland, the island is equipped with solar and wind power, battery storage, a backup generator, a desalination system, and a large freshwater cistern. Access to the island is facilitated by a private helipad and a deep-water dock suitable for boats. The sale also includes a mainland property at 99 E Ocean Drive, which provides private dock space.
This listing represents a significant increase from the island's previous asking price. It was previously listed for $11.7 million in February 2021 before being taken off the market in 2022. The property has now returned to the market at $16 million.
At $16 million, the island's price is more than five times the average single-family home price in the 33050 ZIP code, where the average is approximately $2.91 million. The annual property taxes are reported to be about $25,481.
Listing agents Vladimir Rochebrun and Aaron Rosenthal of The Chad Carroll Group at Compass began marketing the property on August 12. The appeal of the island lies in its complete privacy, offering a location with no neighbors, no homeowner's association, and private beach access.