# 15 Riverside Avenue, Mastic Beach, NY 11951 > **TL;DR:** 4bd/3ba single family, $699,999 ($296/sqft), built 1988, 2,364 sqft. > Waterfront, Hardwood, A/C, 2-car garage. Est. $3,744/mo. Listed 19 days. ## Property at a Glance | Attribute | Value | |-----------|-------| | Price | $699,999 | | Price/sqft | $296 | | Bedrooms | 4 | | Bathrooms | 2 full, 1 half | | Square Feet | 2,364 | | Year Built | 1988 | | Lot Size | 10,890 sqft (0.25 acres) | | Garage | 2-car | | Property Type | Single Family (Single Family Residence) | | Status | Active | | Days on Market | 19 | ## Why This Home Stands Out - **Waterfront** - Waterfront location listed - **Hardwood Floors** - Hardwood flooring listed ## Estimated Monthly Costs | Category | Amount | |----------|--------| | Principal & Interest (20% down, 30-year at 6.5%) | $3,540 | | Estimated Insurance | $204 | | **Total** | **$3,744** | ## Nearby Schools - **Elementary:** Tangier Smith Elementary School - **Middle:** William Paca Middle School - **High:** William Floyd High School ## Key Amenities - Waterfront - Hardwood - A/C - 2-car garage ## Property Highlights - Built in 1988 - 0.25 acre lot - Waterfront ## Description ### Agent Description Breathtaking waterfront views and peaceful sunsets set the stage for this updated 4 Bedroom, 2.5 Bath Hi-Ranch on Poospatuck Creek, with direct access to the bay. The first level features updated flooring, Led lighting, summer kitchen, spacious living room, bedroom, ample storage and sliders to the deck, Cathedral ceilings and hardwood floors create a bright and open feel. This Main level offers two generously sized bedrooms, and a spacious primary with walk in closet and half bath. The remodeled kitchen features quartz countertops, while the living room with fireplace and an oversized picture window showcases the yard and water views. Sliders lead to the upper deck, the perfect place to relax, unwind and savor those spectacular sunsets. Outside the home shines while you enjoy your private dock and a place to launch kayaks and paddleboat. From Poospatuck head to the bay for a day of fishing or simply enjoying life on the water. NEW : 2025/2026 Trex decking on Upper and Lower Level, New Oil tank, New Gutters And Gutter guards ## Location - **Address:** 15 Riverside Avenue, Mastic Beach, NY 11951 - **County:** Suffolk County - **Coordinates:** 40.786427, -72.831104 - **Google Maps:** https://www.google.com/maps?q=40.786427,-72.831104 ## Listing Agent - **Name:** Maralyn C. Diggin CBR - **Brokerage:** Douglas Elliman Real Estate - **Broker Phone:** 5166812600 - **Listing URL:** [View original listing](https://www.realtor.com/realestateandhomes-detail/15-Riverside-Ave_Mastic-Beach_NY_11951_M98377-63916?f=listhub&s=MLSLINY&m=1059003&c=propsimple) ## Photos ![15 Riverside Avenue - Photo 1](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f1635434323r.jpg) ![15 Riverside Avenue - Photo 2](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f1382892467r.jpg) ![15 Riverside Avenue - Photo 3](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f4025557204r.jpg) ![15 Riverside Avenue - Photo 4](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f3639182340r.jpg) ![15 Riverside Avenue - Photo 5](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f1052368207r.jpg) ![15 Riverside Avenue - Photo 6](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f1113044564r.jpg) ![15 Riverside Avenue - Photo 7](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f4049366659r.jpg) ![15 Riverside Avenue - Photo 8](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f683432262r.jpg) ![15 Riverside Avenue - Photo 9](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f3316752951r.jpg) ![15 Riverside Avenue - Photo 10](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f287141546r.jpg) ![15 Riverside Avenue - Photo 11](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f3955260327r.jpg) ![15 Riverside Avenue - Photo 12](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f837118189r.jpg) ![15 Riverside Avenue - Photo 13](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f2000757807r.jpg) ![15 Riverside Avenue - Photo 14](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f4106308592r.jpg) ![15 Riverside Avenue - Photo 15](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f2858190118r.jpg) ![15 Riverside Avenue - Photo 16](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f1865483823r.jpg) ![15 Riverside Avenue - Photo 17](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f2454938148r.jpg) ![15 Riverside Avenue - Photo 18](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f2162568763r.jpg) ![15 Riverside Avenue - Photo 19](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f3276540323r.jpg) ![15 Riverside Avenue - Photo 20](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f2982441566r.jpg) ![15 Riverside Avenue - Photo 21](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f499828099r.jpg) ![15 Riverside Avenue - Photo 22](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f1039818794r.jpg) ![15 Riverside Avenue - Photo 23](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f1566056081r.jpg) ![15 Riverside Avenue - Photo 24](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f830233999r.jpg) ![15 Riverside Avenue - Photo 25](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f3096200758r.jpg) ![15 Riverside Avenue - Photo 26](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f23474689r.jpg) ![15 Riverside Avenue - Photo 27](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f1497783374r.jpg) ![15 Riverside Avenue - Photo 28](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f3460117833r.jpg) ![15 Riverside Avenue - Photo 29](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f200581545r.jpg) ![15 Riverside Avenue - Photo 30](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f948826227r.jpg) ![15 Riverside Avenue - Photo 31](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f837760738r.jpg) ![15 Riverside Avenue - Photo 32](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f922045979r.jpg) ![15 Riverside Avenue - Photo 33](http://lh.rdcpix.com/2ff498c14889814b81d23919bb9ec698l-f3601950741r.jpg) --- **MLS#:** 1059003 | **Updated:** 2026-10-24 **Source:** listhub *Copyright © 2026 OneKey MLS. All rights reserved. All information provided by the listing agent/broker is deemed reliable but is not guaranteed and should be independently verified.* [View on PropertySimple](https://staging.propertysimple.ai/listing/15-riverside-avenue-mastic-beach-ny-11951-5f8130d4096b4ad6bc17a7d65bcf7993) --- ## Structured Data ```json { "@context": "https://schema.org", "@type": "RealEstateListing", "@id": "https://staging.propertysimple.ai/listing/15-riverside-avenue-mastic-beach-ny-11951-5f8130d4096b4ad6bc17a7d65bcf7993#listing", "url": "https://staging.propertysimple.ai/listing/15-riverside-avenue-mastic-beach-ny-11951-5f8130d4096b4ad6bc17a7d65bcf7993", "name": "15 Riverside Avenue, Mastic Beach, NY 11951", "description": "Breathtaking waterfront views and peaceful sunsets set the stage for this updated 4 Bedroom, 2.5 Bath Hi-Ranch on Poospatuck Creek, with direct access to the bay. 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