$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
Occupant Type: Call Listing Agent
Listing Date: 2026-08-12
Status: Active
Original List Price: 16000000
List Price: $16,000,000
Current Price: $16,000,000
Location and Legal
County Or Parish: Monroe
County Parish Name: Monroe
City Name: Marathon
Postal Zip: 33050
Geographic Area: Other
Flood Zone: VE
Country: United States
Street Number: 1
Street Direction Prefix: E
Street Name: Sister Rck
Street Suffix: Island
State Or Province: FL
Postal Code: 33050
Subdivision Name: Off Shore Island
Area: 2980
Parcel Number: 00105590000000
Zoning: 0S
General Property Information
Adjusted Area Main: 2880
Living Area Main: 2304
Lot Size Area: 280628
Water Frontage Feet: 800
Senior Community YN: No
Outdoor Living Spaces YN: Yes
Stories Total: 1
Fireplace YN: Yes
Pool Private YN: Yes
Guest House YN: Yes
Property Sub Type: Single Family Residence
Bedrooms Total: 4
Bathrooms Total: 3
Bathrooms Full: 3
Building Area Main: 5760
Year Built: 2015
Lot Size Acres: 6.44
Waterfront YN: 1
Direction Faces: East
Financial Information
Estimated Monthly Assoc Recurring Fee: 0
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-
Office/Member Information
DXORIGMLSID: SEF
Amenities
Boating: 1
Dining Area
Dining/Living Room: 1
Eat-In Kitchen: 1
Entry Information
Entry Level: 1
Exterior Features
Lighting: 1
Flooring
Tile: 1
Other: 1
Guest House Features
1 Bath: 1
Efficiency: 1
Kitchen: 1
Living Room: 1
Possession
Negotiable: 1
Sewer
Septic Tank: 1
Special Information
Sold As-Is: 1
Heating
Solar: 1
Water Access
No Fixed Bridge: 1
Ocean Access: 1
Water View
Direct Ocean: 1
Ocean: 1
Appliances
Dishwasher: 1
Dryer: 1
Electric Range: 1
Microwave: 1
Oven: 1
Refrigerator: 1
Solar Hot Water: 1
Trash Compactor: 1
Washer: 1
Other: 1
Construction Materials
Block: 1
Interior Features
Bedroom Layout - Three Way Split: 1
Built-in Features: 1
Closet Cabinetry: 1
Levels
One: 1
Listing Terms
Cash: 1
Conventional: 1
Other: 1
Lot Features
Fruit Tree(s): 1
Other Equipment
Satellite Dish: 1
Other: 1
Pool Features
In Ground: 1
Roof
Metal: 1
Water Source
Other: 1
Waterfront Features
Navigable Water: 1
Ocean Front: 1
Boat and Dock Information
Dock: Yes
Boat and Dock Features
Deeded Dock: 1
Private Dock: 1
Cooling
Central Air: 1
Showing Requirements
Appointment Only: 1
Call Listing Agent: 1
Master Bedroom/Bath
Bedroom On Entry Level: 1
Separate Shower: 1
Pool Size Details
Pool Size (WxL): 16x39
Restrictions
No Restrictions: 1
Storm Protection
Impact Glass: Complete
Tax Information
City/County: 1
Outdoor Living Spaces
Deck: 1
Porch: 1
Porch Details
Porch - Open: 1
Porch - Wrap Around: 1
Room Types
Family Room: 1
Price Calculations
Current Price To SqFt: 6944.44
Section Details
Parcel Number MLX: 0010
Acreage Description
5 To Less Than 10 Acre Lot: 1
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 - 10 - 2026
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