
1230 S River St Marshfield — Photo 1 of 42
$2,495,000
Investment Analysis — 1230 S River St
Marshfield, MA 02050
Based on HUD Small Area Fair Market Rent for Boston-Cambridge-Quincy, MA-NH HUD Metro FMR Area, a 4-bedroom in 02050 carries an estimated $3,390/mo in gross rent — about a 0.30% cap rate and $7,545/yr in estimated NOI at the $2,495,000 list price. Adjust every assumption in the calculator below.
Beds
4
Baths
3.5
SqFt
4,850
Style
Single Family
Built
1890
Welcome to Seacrest, also known as the Coast Guard Mansion—an extraordinary estate set high on a commanding hilltop with sweeping panoramic views across the South River to the Atlantic Ocean beyond. More than a residence, Seacrest is a local landmark, a home that has stood witness to more than a century of history and now presents a remarkable opportunity.The estate’s distinctive design has been attributed to Richard Morris Hunt, the celebrated American architect of the Gilded Age whose work helped define some of the country’s most iconic estates. From the moment you arrive, Seacrest possesses a presence that is increasingly rare, grand yet inviting, architecturally significant yet wonderfully livable.Step inside and the craftsmanship immediately takes center stage. A magnificent wood central staircase rises from the entry hall to a dramatic upper walkway connecting the home’s two wings, creating an unforgettable architectural focal point. The spectacular great room soars to approximately twenty-foot ceilings, while the formal dining room is wrapped in rare tiger-eye maple paneling, lending warmth, depth, and character. A handsome mahogany-paneled office provides another richly detailed space.Extensive renovations and thoughtful updates have enhanced Seacrest while respecting the architecture that makes it so special. A significant renovation by respected South Shore architectural firm introduced a beautifully appointed custom center-island kitchen and reimagined primary suite, seamlessly blending modern comfort with the home's original character. Numerous additional improvements and custom details throughout further elevate the property for today's lifestyle.Offering approximately 4,880 square feet, twelve rooms, four bedrooms and four bathrooms, Seacrest provides an exceptional combination of grand entertainment spaces and comfortable private retreats. Its gracious proportions, extraordinary millwork, six fireplaces, custom windows, and irreplaceable architectural details create a home unlike anything being built today.Set on 2.86 private acres, the estate enjoys a timeless exterior and a spectacular elevated setting. Seacrest is more than a beautiful home. It is a piece of South Shore history—a landmark property where architecture, craftsmanship, privacy, and breathtaking coastal views come together in a way that simply cannot be recreated.
ADU Potential
Massachusetts allows one accessory dwelling unit by right in single-family zoning districts statewide (M.G.L. c. 40A §3; 760 CMR 71.00, effective Feb 2025). Estimated maximum ADU size for this property: 900 sq ft (the lesser of 900 sq ft or half the 4,850 sq ft principal dwelling). Lot size: 124,582 sq ft.
Based on listing data, which indicates the property type — not the zoning district. Local dimensional, septic (Title 5), and historic-district requirements still apply. Not legal advice — verify with the municipality.
Estimates — not financial advice
These figures are illustrative estimates for informational purposes only — not an appraisal, valuation, or guarantee of rent, income, or returns, and not financial, tax, or investment advice. Rent is either the figure reported on the MLS listing — in-place rent that may differ from market and is not verified against the actual leases — or, where the listing reports none, an estimate from HUD Small Area Fair Market Rents, a government benchmark that may differ from actual market rent. Each figure is labelled with its source. Cap rate, NOI, and returns depend on the assumptions shown, which you can change. MLS and other third-party data may be inaccurate or out of date. Verify all figures independently and consult your own financial, tax, and legal advisors before making any investment decision.
Property Details
Financials
Parking
Interior Specifications
Climate & Utilities
Building & Exterior
Property & Lot
Amenities & Appliances
Oven • Dishwasher • Microwave • Refrigerator • Range Hood
Neighborhood
Public Transportation • House of Worship • Marina • Public School • T-Station
Geography
Floorplan Breakdown
Structural Layout
Living Room
Lvl FirstCathedral Ceiling(s), French Doors, Lighting - Overhead, Decorative Molding
Dining Room
Lvl FirstFlooring - Wood, French Doors, Lighting - Overhead, Decorative Molding, Pocket Door
Kitchen
Lvl FirstCountertops - Stone/Granite/Solid, Kitchen Island, Cabinets - Upgraded, Recessed Lighting, Remodeled, Wine Chiller, Gas Stove
Office
Lvl FirstFlooring - Hardwood, Lighting - Overhead
Family Room
Lvl FirstFlooring - Wood, French Doors, Lighting - Overhead, Decorative Molding
Primary Bedroom
Lvl SecondBathroom - Full, Flooring - Hardwood, Balcony / Deck, French Doors
Bedroom 2
Lvl SecondBedroom 3
Lvl SecondFlooring - Hardwood, Lighting - Overhead
Bedroom 4
Lvl SecondBathroom - Full, Flooring - Hardwood, Lighting - Overhead
Listing Agent: Amy March
Listing Office: The Firm
MLS® Number: 73577993