Seal Harbor is a saltwater beach in Hancock County, Maine. Across 67 bacteria samples collected between 2021 and 2025 at nearby monitoring stations, it earns a Beach Safety Grade of D — Poor.
About 18% of samples at Seal Harbor exceeded the EPA Beach Action Value of 104 CFU/100 mL for Enterococcus — the threshold at which water managers typically post a swimming advisory. In practice that means the safe-swimming limit was frequently crossed here over the monitored period. Bacteria samples frequently exceed the safe-swimming threshold; swimming advisories are common here.
Seal Harbor was not under a swimming advisory in the most recent EPA snapshot. Conditions can change quickly after heavy rain or high runoff, so it's still worth checking the current advisory the day you go.
📍 44.2960, -68.2390 · Open in Google Maps. Coordinates mark the monitored shoreline, not a specific access point.
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Common questions
Frequently Asked Questions
Seal Harbor earns a Beach Safety Grade of D (Poor), based on 67 bacteria samples where about 18% exceeded the EPA safe-swimming threshold. Always confirm the current advisory before swimming, especially after heavy rain.
Water samples near Seal Harbor are tested for Enterococcus, uploaded to the EPA Water Quality Portal. A sample above the Beach Action Value (104 CFU/100 mL) signals a higher risk of illness from swimming. BeachGrade summarizes multiple years of those results into one grade.
Seal Harbor is a saltwater beach in Hancock County, Maine.
Beach inventory and advisory status from the U.S. EPA BEACON program; bacteria samples from the Water Quality Portal. The Beach Safety Grade summarizes multiple years of monitoring — see our methodology. Water quality changes quickly, especially after rain; always check the official state or county advisory before swimming. BeachGrade is informational and not a substitute for official public-health guidance.