waterfront
Pool: In Ground
Pool: Equipment Included
View: Pool

$18,500,000

631 N Mashta Drive, Key Biscayne, FL 33149

Boat up to approx. 50' LOA — preliminary estimate, verify

Estimate only, not guaranteed. Verify before you buy or sell. Boat length is a preliminary estimate from the water frontage, not a stated dock length — verify the berth before relying on it. Saved Cape Florida Channel route. Charted route depth is not a surveyed private-dock depth or confirmed boat draft; uncovered stretches need verification.

Key Biscayne, FL, 33149

4 bd · 5 ba · 2,255 sqft · 100 ft of water

Listed by Coldwell Banker

Ask Simon about boat size

Max boat: 50 ft · Dock: Not provided

10

min · est.

2.3 nm

5.9 ft

low tide depth

Enter draft

0 fixed · 0 opening

bridges on the route

Ask Simon

Run to the ocean

Cape Florida ChannelDock

Map © Esri · saved route, planning only

Blue · deep enoughOrange · tide neededRed · too shallowGray dashed · canal, not surveyed

Water depth on the way out

Dock4 ft est.Leg 25.9 ftLeg 65.9 ft est.West Mashta DLeg 74 ft est.Leg 85.9 ft est.Leg 117.9 ftLeg 139 ft est.Inlet5.9 ft

Charted route depths do not confirm private dock depth, current shoaling or safe passage; verify with your captain.

Today’s tide · Eastern time

Current tide prediction not provided — Ask Simon

Route bridges & sources

Bridges on the route

West Mashta Drive. · type unconfirmed · clearance not provided

Depth sources

NOAA chart (updated weekly)

Tides

Tides: NOAA tide predictions, nearest station

Estimate only, not guaranteed. Verify before you buy or sell.

Know your costs before you buy

Work through three numbers: your estimated monthly payment, the cash needed at closing, and insurance & flood.

Estimated Monthly Payment

$116,898/ month

20% down · 6.75% interest · 30-year loan · Jumbo loan

Jumbo loan: put down about $17,667,250 or more to stay conforming. What's different?
  • A bigger down payment, often 10–20% or more
  • A higher credit score, often 700+
  • More cash reserves, often 6–12 months of payments
  • Full income documentation, sometimes a second appraisal on large loans

Other options: Conforming first mortgage plus a home equity loan for the rest ("piggyback"); Portfolio or private bank loans; Cash. Each lender sets its own rules.

Principal, interest, taxes and insurance. Property Tax (after sale). Estimated; not a lender quote.

Principal & interest
$95,993/mo
Property tax (after sale) est.
$19,930/mo
Homeowners insurance est.
$975/mo
HOA
$0/mo

Estimate only, not guaranteed. Verify before you buy or sell.

About This Property

Find similar homes

BRING ALL OFFERS! Exceptional waterfront opportunity in prestigious Key Biscayne. Set on a 15,000 sq. ft. lot with 100 feet of water frontage, this residence offers open-water views, direct Biscayne Bay access, and no fixed bridges to the ocean. Currently undergoing a complete renovation, it will feature modern finishes, impact windows and doors, new systems, spacious living areas, a chef's kitchen, and luxurious bathrooms. Enjoy a private dock, deep-water access, pool, breathtaking sunsets, and an unmatched boating lifestyle in one of South Florida's most desirable communities One of the most compelling waterfront opportunities currently available in all of Key Biscayne. Perfectly positioned on the exclusive and highly coveted Mashta Island, this exceptional property offers approximately 100 feet of prime waterfront, deep-water dockage, direct Biscayne Bay access, and no fixed bridges to the Atlantic Ocean, creating an unparalleled opportunity for boating enthusiasts and yacht owners. Mashta Island has long been recognized as one of South Florida's most prestigious residential enclaves, offering exceptional privacy, quiet tree-lined streets, oversized waterfront estates, and immediate access to the open waters of Biscayne Bay while remaining only minutes from Brickell, Downtown Miami, Coconut Grove, Coral Gables, Miami Beach, and Miami International Airport. Very few neighborhoods offer this combination of island living, security, boating lifestyle, and proximity to the city's financial and cultural centers. The residence is currently on renovation designed to transform the property into a contemporary waterfront estate while preserving the exceptional value of its location and oversized waterfront parcel. This is substantially more than a cosmetic renovation. The project includes major improvements throughout the residence, including redesigned living spaces, upgraded electrical and plumbing systems, new HVAC equipment, impact-resistant windows and doors, premium flooring, modern architectural lighting, designer finishes, and a completely reimagined interior intended to meet today's luxury lifestyle expectations. Upon completion, the home is anticipated to offer spacious entertaining areas, beautifully appointed bedroom suites, bathrooms, an impressive chef's kitchen featuring custom cabinetry, premium appliances, elegant countertops, and thoughtfully designed indoor-outdoor living spaces that maximize the spectacular waterfront setting. The property's exceptional orientation provides beautiful water views and unforgettable sunsets while creating an ideal environment for entertaining, family gatherings, and year-round outdoor living. The expansive backyard offers generous space surrounding the swimming pool together with multiple areas for outdoor dining, lounging, and enjoying the waterfront lifestyle that has made Key Biscayne one of the most desirable residential communities in South Florida. For boating enthusiasts, few properties can offer the combination of oversized waterfront, private dockage, deep-water access, and unrestricted navigation to Biscayne Bay and the Atlantic Ocean without fixed bridges. Whether accommodating a large sport yacht, cruising yacht, center console, or multiple vessels, the waterfront configuration provides flexibility rarely available in today's market. Key Biscayne continues to be recognized as one of South Florida's most exclusive island communities, celebrated for its pristine beaches, excellent schools, private clubs, marinas, tennis facilities, parks, bicycle paths, restaurants, and relaxed coastal lifestyle. Residents enjoy the unique advantage of living within a peaceful island environment while remaining only a short drive from Miami's world-class shopping, fine dining, cultural institutions, private airports, international business centers, and professional sports venues. The supply of premium waterfront homes on Mashta Island remains extremely limited due to the neighborhood's established character and finite number of waterfront parcels. As a result, opportunities to acquire large waterfront lots with substantial dockage and direct ocean access continue to be highly sought after by both domestic and international buyers. The combination of location, waterfront dimensions, boating accessibility, oversized lot, and comprehensive renovation creates a property with exceptional long-term appeal. Showings are strictly by appointment with the Listing Agent.. All measurements, dimensions, lot size, square footage, waterfront frontage, dock dimensions, room sizes, zoning, taxes, permits, specifications, plans, renderings, and property information are believed to be accurate but are not guaranteed and should be independently verified by Buyer. Renderings, conceptual plans, floor plans, specifications, and construction updates are available upon request when applicable. This offering represents an extraordinary opportunity to secure one of Key Biscayne's waterfront residences . Whether as a primary residence, seasonal retreat, or long-term investment, this property combines one of South Florida's most desirable locations with an outstanding boating lifestyle and exceptional future value. Bring All Offers.

Good deal

Why we flagged this one

A transparent review of current MLS facts—not a paid placement.

  • 99 days on market

    Longer time on market usually means the seller is more open to negotiating on price and terms.

Price reductions and days on market come from this listing's MLS record. This is an initial market signal, not a formal appraisal or full comparable market analysis.

Your costs (est.)

≈ $116,898/mo

631 N Mashta Drive, Key Biscayne, FL 33149 · Key Biscayne

Location

631 N Mashta Drive, Key Biscayne, FL 33149

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Simon Gedz, South Florida luxury real estate specialist

Simon Gedz

Realtor® since 1995