Mariner's Isle San Mateo, CA
East of 101 near the Marina Lagoon, with condos, townhomes and single-family homes.
Living in Mariner's Isle
Mariner's Isle is east of Highway 101 in San Mateo on the Marina Lagoon, which was originally called Seal Slough until developers decided the name wouldn't attract buyers. Its single-family homes and waterfront condos date mostly from the 1960s and '70s, and like neighboring Foster City it has a planned, waterfront feel; condos and townhomes make up most of the sales. Single-family homes have a 12-month median around $1.6M, and the condo median was about $752K in 2025.
Parking & walkability: Condo and townhome complexes include assigned parking with more limited guest spaces, and single-family homes have driveways and garages. The lagoon paths and Bay Trail are close by, Bridgepointe's shopping is a short drive, and Highway 92 and 101 are a few minutes away.
What homes in Mariner's Isle are doing
Single-family homes in Mariner's Isle sold for a median of about $1.03M in 2015–16 and $1.66M in 2024–25, a 61% increase, roughly in line with San Mateo as a whole (+63%). Prices peaked in 2024 at $1.74M. In 2025, homes here sold at a moderate pace (median 30 days on market) and close to asking (99.8% of list price on average). So far in 2026 (5 sales through September), the median is $1.63M.
Median single-family price, 2015–2026
* 2026 covers January through September. Hollow dots mark years with fewer than 3 single-family sales; treat those medians as rough. 99 single-family sales since 2015.
| Year | Sales | Median price | $/sq ft | Days on market | Sale-to-list |
|---|---|---|---|---|---|
| 2026 (Jan–Sep) | 5 | $1.63M | $1,152 | 11 | 98.7% |
| 2025 | 3 | $1.53M | $1,141 | 30 | 99.8% |
| 2024 | 5 | $1.74M | $1,075 | 26 | 102.2% |
| 2023 | 12 | $1.65M | $973 | 12 | 103.6% |
| 2022 | 5 | $1.7M | $1,015 | 11 | 100.0% |
| 2021 | 16 | $1.6M | $906 | 10 | 104.6% |
| 2020 | 7 | $1.52M | $790 | 19 | 100.0% |
| 2019 | 6 | $1.56M | $807 | 17 | 99.6% |
| 2018 | 8 | $1.35M | $874 | 24 | 105.8% |
| 2017 | 8 | $1.28M | $810 | 12 | 107.4% |
| 2016 | 6 | $1.23M | $687 | 27 | 99.1% |
| 2015 | 18 | $970K | $619 | 16 | 106.0% |
Condos & townhomes in Mariner's Isle (269 sales since 2015)
| Year | Sales | Median price | $/sq ft | Days on market | Sale-to-list |
|---|---|---|---|---|---|
| 2026 (Jan–Sep) | 9 | $915K | $821 | 40 | 97.2% |
| 2025 | 22 | $752K | $814 | 25 | 98.9% |
| 2024 | 19 | $800K | $894 | 20 | 99.3% |
| 2023 | 18 | $899K | $882 | 9 | 100.0% |
| 2022 | 35 | $1M | $869 | 27 | 99.9% |
| 2021 | 28 | $753K | $834 | 25 | 100.0% |
| 2020 | 19 | $1.08M | $883 | 28 | 100.0% |
| 2019 | 22 | $750K | $777 | 10 | 100.8% |
| 2018 | 22 | $908K | $910 | 9 | 112.4% |
| 2017 | 23 | $685K | $737 | 13 | 101.4% |
| 2016 | 28 | $623K | $688 | 15 | 101.9% |
| 2015 | 24 | $588K | $639 | 11 | 102.4% |
Mariner's Isle on the map
Borders are built lot by lot from the county's property lines and where homes have been listed (MLS neighborhood codes), and stay inside official city limits (dashed), so a home or two along an edge may differ from official MLS lines.
Other San Mateo neighborhoods
- Baywood
- San Mateo Park
- Aragon
- Hayward Park
- Sugarloaf & Laurelwood
- Shoreview & Seal Point
- Beresford & Hillsdale
- 19th Avenue Park & Sunnybrae
- Baywood Knolls
- Baywood Park
- Bowie Estate
- Eastern Addition & Downtown
- Edgewater Isle
- Fiesta Gardens
- Foothill Terrace
- Harbortown
- Homestead & Husing
- Lakeshore
- Lauriedale
- Los Prados
- Parkside
- San Mateo Knolls & Laurel Creek
- San Mateo Terrace
- San Mateo Village & Glendale Village
- San Mateo Woods & Bayridge
- The Highlands & Ticonderoga
- Westwood Knolls
Thinking about buying or selling in Mariner's Isle?
I can pull the exact comps for your street and walk you through what they mean.
Source: MLSListings, Inc. closed sales, 2015–September 2026, summarized by Drew Lehr. Neighborhood figures combine the MLS area(s) that make up Mariner's Isle; where there are several, yearly figures are sales-weighted. Information deemed reliable but not guaranteed.