$16,000,000
Marathon, FL 33050
MLS# A12069701
4 beds | 3 baths | 5760 sqft
1 / 25
Property Description
Own an entire private island in the Florida Keys, just ¼ mile offshore from Marathon! East Sister Rock Island offers extraordinary privacy surrounded by turquoise waters, yet is only minutes from the mainland. The property encompasses approx. 6.5 acres, including approx. 5.8 acres of surrounding seabed, creating an exceptional marine setting for snorkeling, swimming, kayaking, paddleboarding, fishing and watersports. The beautifully updated 3-bedroom, 2-bath main residence and detached guest house offer over 5,000 total SF of living and entertaining space. Recent renovations include an updated kitchen with gorgeous countertops and modern finishes. A 12-ft-wide wraparound veranda captures panoramic water views, sunrises and spectacular Keys sunsets. Amenities include a waterfront pool and spa, tropical landscaping, outdoor entertaining areas, and a 100-ft deep-water dock. Self-sufficient infrastructure includes solar and wind power, battery storage, backup generator, desalination system and freshwater cistern capacity. Private helipad provides additional access. Seller is open to select Joint Venture opportunities.
Details
Maps
Contract Information
Comp Sale YN: No
Listing Date: 2026-08-12
Status: Active
Original List Price: 16000000
List Price: $16,000,000
Current Price: $16,000,000
Occupant Type: Call Listing Agent
Location and Legal
Country: United States
County Or Parish: Monroe
County Parish Name: Monroe
Street Number: 1
Street Direction Prefix: E
Street Name: Sister Rck
Street Suffix: Island
City Name: Marathon
State Or Province: FL
Postal Code: 33050
Postal Zip: 33050
Subdivision Name: Off Shore Island
Area: 2980
Geographic Area: Other
Parcel Number: 00105590000000
Zoning: 0S
Flood Zone: VE
General Property Information
Property Sub Type: Single Family Residence
Bedrooms Total: 4
Bathrooms Total: 3
Bathrooms Full: 3
Building Area Main: 5760
Living Area Main: 2304
Adjusted Area Main: 2880
Year Built: 2015
Lot Size Area: 280628
Lot Size Acres: 6.44
Senior Community YN: No
Guest House YN: Yes
Waterfront YN: 1
Water Frontage Feet: 800
Outdoor Living Spaces YN: Yes
Stories Total: 1
Direction Faces: East
Fireplace YN: Yes
Pool Private YN: Yes
Financial Information
Membership Fee Required YN: No
Tax Annual Amount: 25482
Tax Year: 2025
Tax Legal Description: 23 66 32 LOT 2 (US PATENT 1186533) EAST SISTER ROCK AND ADJACENT BAY BOTTOM G71-513(II DEED 20369) OR374-139/40 OR752-1640 OR752-1642 OR755-
Entry Information
Entry Level: 1
Boat and Dock Information
Dock: Yes
Pool Size Details
Pool Size (WxL): 16x39
Storm Protection
Impact Glass: Complete
Price Calculations
Current Price To SqFt: 6944.44
Section Details
Parcel Number MLX: 0010
Status Change Information
Major Change Timestamp: 2026-08-12T04:00:00Z
Major Change Type: New Listing
Status Change Date: 2026-08-12
Originating Details
Originating System Key: 548040636
Originating System ID: M00000151
Property Features
Dining Area: Dining/Living Room; Eat-In Kitchen
Exterior Features: Lighting
Flooring: Tile; Other
Guest House Features: 1 Bath; Efficiency; Kitchen; Living Room
Appliances: Dishwasher; Dryer; Electric Range; Microwave; Oven; Refrigerator; Solar Hot Water; Trash Compactor; Washer; Other
Boat and Dock Features: Deeded Dock; Private Dock
Construction Materials: Block
Cooling: Central Air
Heating: Solar
Interior Features: Bedroom Layout - Three Way Split; Built-in Features; Closet Cabinetry
Levels: One
Listing Terms: Cash; Conventional; Other
Lot Features: Fruit Tree(s)
Other Equipment: Satellite Dish; Other
Pool Features: In Ground
Possession: Negotiable
Restrictions: No Restrictions
Roof: Metal
Sewer: Septic Tank
Special Information: Sold As-Is
Tax Information: City/County
Water Access: No Fixed Bridge; Ocean Access
Water Source: Other
Water View: Direct Ocean; Ocean
Waterfront Features: Navigable Water; Ocean Front
Showing Requirements: Appointment Only; Call Listing Agent
Outdoor Living Spaces: Deck; Porch
Porch Details: Porch - Open; Porch - Wrap Around
Room Types: Family Room
Acreage Description: 5 To Less Than 10 Acre Lot
Room Information
| Room Name |
| Family Room |
Listing Office: Compass Florida, LLC
Last Updated: September - 15 - 2026
This information is not verified for authenticity or accuracy and is not guaranteed and may not reflect all real estate activity in the market. Copyright 2026 Beaches Multiple Listing Service, Inc. All rights reserved. Information Not Guaranteed and Must Be Confirmed by End User. Site contains live data.