1 E Sister Rck Island, Marathon, FL 33050 (MLS# A12069701)

1 E Sister Rck Island, Marathon, FL 33050

$16,000,000

Virtual Tour

https://www.propertypanorama.com/instaview/mia/A12069701

Property Type: Residential Bedrooms: 4 Baths: 3 Square Footage: 5,760 Status: Active

Current Price: $16,000,000 List Date: 8/12/2026 Last Modified: 9/15/2026

Overview

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.

Listing Details MLS# A12069701

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: Yes
Water Frontage Feet: 800
Outdoor Living Spaces YN: Yes
Stories Total: Yes
Direction Faces: East
Fireplace YN: Yes
Pool Private YN: Yes

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

Contract Information

Comp Sale YN: No
Original List Price: 16000000
Occupant Type: Call Listing Agent

Location and Legal

Country: United States
County Or Parish: Monroe
County Parish Name: Monroe
Street Number: Yes
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

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-
Estimated Monthly Assoc Recurring Fee: 0

Status Change Information

Major Change Timestamp: 2026-08-12T04:00:00Z
Major Change Type: New Listing
Status Change Date: 2026-08-12

More Information

Entry Information

Entry Level: Yes

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

Originating Details

Originating System Key: 548040636
Originating System ID: M00000151

Office/Member Information

DXORIGMLSID: SEF

Amenities

Boating: Yes

Dining Area

Dining/Living Room: Yes
Eat-In Kitchen: Yes

Exterior Features

Lighting: Yes

Flooring

Tile: Yes
Other: Yes

Guest House Features

1 Bath: Yes
Efficiency: Yes
Kitchen: Yes
Living Room: Yes

Possession

Negotiable: Yes

Sewer

Septic Tank: Yes

Special Information

Sold As-Is: Yes

Heating

Solar: Yes

Water Access

No Fixed Bridge: Yes
Ocean Access: Yes

Water View

Direct Ocean: Yes
Ocean: Yes

Appliances

Dishwasher: Yes
Dryer: Yes
Electric Range: Yes
Microwave: Yes
Oven: Yes
Refrigerator: Yes
Solar Hot Water: Yes
Trash Compactor: Yes
Washer: Yes
Other: Yes

Construction Materials

Block: Yes

Interior Features

Bedroom Layout - Three Way Split: Yes
Built-in Features: Yes
Closet Cabinetry: Yes

Levels

One: Yes

Listing Terms

Cash: Yes
Conventional: Yes
Other: Yes

Lot Features

Fruit Tree(s): Yes

Other Equipment

Satellite Dish: Yes
Other: Yes

Pool Features

In Ground: Yes

Roof

Metal: Yes

Water Source

Other: Yes

Waterfront Features

Navigable Water: Yes
Ocean Front: Yes

Boat and Dock Features

Deeded Dock: Yes
Private Dock: Yes

Cooling

Central Air: Yes

Showing Requirements

Appointment Only: Yes
Call Listing Agent: Yes

Master Bedroom/Bath

Bedroom On Entry Level: Yes
Separate Shower: Yes

Restrictions

No Restrictions: Yes

Tax Information

City/County: Yes

Outdoor Living Spaces

Deck: Yes
Porch: Yes

Porch Details

Porch - Open: Yes
Porch - Wrap Around: Yes

Room Types

Family Room: Yes

Acreage Description

5 To Less Than 10 Acre Lot: Yes

Room Information

Family Room

Listing Office: Compass Florida, LLC

Last Updated: September - 15 - 2026

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