Located a quarter-mile off-shore Marathon, FL, East Sister Rock Island is a small and private oasis surrounded by sand and coral reef.

E Sister Rock Island, Marathon FL

For sale: $12,000,000

Many homes in the Florida Keys boast private beachfront and spectacular water views. Few, however, can lay claim to having a 360-degree beachfront, but this special private island home does.

Located a quarter-mile off the Atlantic shore of Marathon, FL, this small and private oasis on East Sister Rock Island is surrounded by white sand and coral reef.

Although the city of Marathon includes several keys and smaller private islands, the property is unusual for the size of its home, explains listing agent Marvin Arrieta.

“If they [the islands] have a home, it’s a little house,” said Arrieta. “This house is 5,000 square feet.”

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The Marathon home for sale is completely off-the-grid, relying on solar panels on the roof and side of the house for power, and cisterns collect rainwater.

Built in 1980 as a family getaway spot, the home holds all the vacation essentials: a wrap-around porch measuring 2,700 square feet, private dock and 21-foot-long boat, which is included in the sale. The island also has a helipad for ease of transportation to the Marathon and Miami airports.

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The Bahamas-style residence was updated in 2001 and features enormous windows and 19 sliding glass doors that open out to veranda. In addition to the three bedrooms and two bathrooms in the main home, there is a smaller, detached 1-bedroom, 1-bathroom guest house.

The owners, according to Arrieta, are listing the property because they no longer use the island as often as they’d like.

“When they bought this property, they had one small child and they spent a lot of time there [on the island],” he said. “Now they have four children that are almost grown and they don’t go to the island.”

The property is designed to be a vacation paradise. The coral reef surrounding the home is perfect for snorkeling and just off the home’s shores are plenty of fishing areas or other opportunities for water sports, explained Arrieta.

If you find the $12 million price tag a bit too much too swallow at once, the private isle is also available for rent: $5,000 a week.

According to Zillow’s mortgage calculator, a monthly payment on the private island would currently be $44,803 assuming a 20 percent down payment on a 30-year-mortgage.