1 E Sister Rock Island, Marathon, FL 33050

New Listing

$16,000,000

Property Type: Residential Bedrooms: 4 Baths: 3 Square Footage: 2,304 Lot Size (sq. ft.): 280,526 Status: Active

Current Price: $16,000,000 List Date: 8/12/2026 Last Modified: 8/13/2026

Overview

Description

Own an entire private island in the heart of the Florida Keys. Located just ¼ mile offshore from Marathon, East Sister Rock Island offers extraordinary privacy surrounded by turquoise waters, yet remains only minutes from the mainland. The property encompasses approximately 6.5 acres, including approximately 5.8 acres of surrounding seabed that create an exceptional marine setting for snorkeling, swimming, kayaking, paddle boarding, fishing and exploring the crystal-clear waters of the Keys. At the center of the island is a beautifully updated 3-bedroom, 2-bath main residence with a detached guest house, offering over 5,000 total SF of living and entertaining space. Recent interior renovations include a beautifully updated kitchen with gorgeous countertops and modern finishes. A 12-foot-wide wraparound veranda captures panoramic water views, Atlantic sunrises and spectacular Florida Keys sunsets. Designed for the ultimate island lifestyle, the property features a waterfront p ... (Read more)

Listing Details MLS# 620952

Location, Tax & Legal

Street #: Yes
Direction: E
Street Name: Sister Rock Island
Key/Island: Marathon
State/Province: FL
Zip Code: 33050
County: Monroe
Subdivision: Misc Sombrero Area (50.0)
Area: 14 - Sombrero Area
City: MARATHON
Mile Marker: 50
Marathon Neighborhood: Sombrero
Side: Ocean
Alternate Key #: 1124222
Parcel #: 00105590000000
Zoning: RM-1 - Residential Medium - 1
Deed Restrictions: Unknown
Legal: 23 66 32 Lot 2 (Us Patent 1186533) East Sister Rock And Adjacent Bay Bottom G71-513(Ii Deed 20369) Or374-139/40 Or752-16
Taxes: 25481.52
Tax Year: 2025
Pub Sewer HkUp: No

Contract Information

Listing Board: Marathon/Lower Keys

General Property Description

Realtor.COM Type: Residential - Single Family
Style: Off Shore Island
Waterfront: Yes
Control Depth: 3
Pool: Yes
Year Built: 1980
Lot SqFt: 280526
Lot Sqft Source: Tax Records
Acres: 6.44
Living Apx SqFt: 2304
SqFt Source: Tax Records
Total Bedrooms: 4
Full Baths: 3
Total Baths: 3
Rentals Allowed: Yes

Association Info

Mandatory Home Owners Asc: No
1st Right of Refusal: No
Association Fee $: 0

License Info

Transient Rntl Licns: Yes

More Information

Dockage

Dock Length: 100
Dock: Wood

Building Style

Above Flood: Unknown
Stories: 1 Story

Remarks & Misc

Remarks – Consumer: Own an entire private island in the heart of the Florida Keys. Located just ¼ mile offshore from Marathon, East Sister Rock Island offers extraordinary privacy surrounded by turquoise waters, yet remains only minutes from the mainland. The property encompasses approximately 6.5 acres, including approximately 5.8 acres of surrounding seabed that create an exceptional marine setting for snorkeling, swimming, kayaking, paddle boarding, fishing and exploring the crystal-clear waters of the Keys. At the center of the island is a beautifully updated 3-bedroom, 2-bath main residence with a detached guest house, offering over 5,000 total SF of living and entertaining space. Recent interior renovations include a beautifully updated kitchen with gorgeous countertops and modern finishes. A 12-foot-wide wraparound veranda captures panoramic water views, Atlantic sunrises and spectacular Florida Keys sunsets. Designed for the ultimate island lifestyle, the property features a waterfront pool and spa, tropical landscaping, multiple outdoor lounging and dining areas, and a 100-foot deep-water dock with ample dockage. World-class fishing, diving, snorkeling, boating and water-sports begin just outside your door. East Sister Rock is equipped for self-sufficient island living with solar and wind power, battery storage, backup generator, desalination system and substantial freshwater cistern capacity. A private helipad provides an additional point of access. Few properties offer this combination of privacy, accessibility, marine surroundings and established island infrastructure. Seller is also open to exploring select Joint Venture opportunities. Note the sale includes 99 E Ocean Drive on the mainland which has a private dock space.

Fee Includes

None: Yes

Tax Exemptions

None: Yes

Appliances

Dishwasher: Yes
Dryer: Yes
Microwave: Yes
Oven: Yes
Range: Yes
Refrigerator: Yes
Stainless Steel Appliance(s): Yes
Washer: Yes

Pets

Pets Allowed: Yes

Cooling

Central Air: Yes

Heating

Central: Yes

Waterfront

Oceanfront: Yes

Waterview

Ocean View: Yes
Open Water View: Yes

Floor

Tile: Yes
Wood: Yes

Interior Features

Bar: Yes
Built-in Cabinets: Yes
Granite Counter Top: Yes
Walk-in Closet(s): Yes

Windows/Doors

Impact Rstnce Window: Yes

Security

Other: Yes

Construction

CBS: Yes
Concrete: Yes

Land Size

5 Less Than 10 Acres: Yes

Terms

Cash: Yes
Conventional: Yes
Seller Finance Psble: Yes
Other Specify: Yes

Utilities

Satellite Dish: Yes
Septic Tank: Yes
Solar Power: Yes
Whole House Generatr: Yes

Porch/Balcony

Deck: Yes
Open Porch/Balcony: Yes

Exterior Features

Detached Guest Qtrs: Yes

Pool Info

In Ground: Yes
Decked: Yes

Roof

Metal Roof: Yes

Shutters

Accordion: Yes

Property Features

Fee Includes: None Tax Exemptions: None Waterfront: Oceanfront Waterview: Ocean View; Open Water View Cooling: Central Air Heating: Central Utilities: Satellite Dish; Septic Tank; Solar Power; Whole House Generatr Interior Features: Bar; Built-in Cabinets; Granite Counter Top; Walk-in Closet(s) Appliances: Dishwasher; Dryer; Microwave; Oven; Range; Refrigerator; Stainless Steel Appliance(s); Washer Exterior Features: Detached Guest Qtrs Pool Info: In Ground; Decked Construction: CBS; Concrete Shutters: Accordion Floor: Tile; Wood Roof: Metal Roof Pets: Pets Allowed Security: Other Land Size: 5 Less Than 10 Acres Terms: Cash; Conventional; Seller Finance Psble; Other Specify

Room Information

Room Name	Level
Bedroom 1	Main
Bedroom 2	Main
Bedroom 3	Main
Full Bathroom	Main
Full Bathroom	Main

Listing Office: Compass Florida, LLC

Last Updated: August - 13 - 2026

The data relating to real estate for sale on this web site comes in part from the Florida Keys MLS, Inc. Information provided is deemed reliable but not guaranteed. All properties are subject to prior sale, change or withdrawal. The information being provided is for consumers’ personal, non-commeral use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. IDX data is deemed reliable but is not guaranteed accurate by the MLS.

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