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Map of White Horse Beach (Flag Rock)
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Shore entry

White Horse Beach (Flag Rock)

Massachusetts, United States
Open Water suggested2–9 m depthShore entry5mm wetsuit typical

White Horse Beach (Flag Rock) at a glance

White Horse Beach (Flag Rock) is a shore dive site in Massachusetts, United States with depths of 1.5–9.1 m (5–30 ft). Typically most favorable Jul–Aug · from 3 years of archive data. Divers commonly see American lobster, Rock crab, and Cunner. Recent reports put the water around 21°C (70°F). Check the latest conditions and entry details before you go.

Marine model · graded 4h ago
0.2 mwaves — under half a meter expected

Tap a factor for its source and model point · Forecast 21°C · seasonal avg 18°C

Site hazards: Shallow rocky bottom around Flag Rock with surge on onshore (easterly) winds; cold water; summer swimmers; very limited legal parking in season.

Read the full hazards ↓

Dive windows this week

Best: Sat
Sun6:00–21:00
Mon6:00–21:00
Tue6:00–21:00
Wed6:00–21:00
Thu6:00–16:00
Fri6:00–21:00
Sat6:00–21:00

Favorable windowModerate window— no window

First light 4:58 · Sunrise 5:30 · Sunset 20:07

Source: Open-Meteo marine · model point 12 km from site · graded 4h ago

Forecast only — always assess conditions on site.

Forecast · NOAA tide model

Tide & slack timing

Loading tide predictions

Recent diver reports

Dated firsthand observations from divers — not current conditions.

No diver reports for this site yet. — one dated observation helps every diver after you.

What Divers Say

Known for: American lobster, Rock crab, Cunner
Best time: At or near high tide (maximum depth ~30-35 ft only on the highest tides); calm days without onshore easterly wind; off-season for easy parking. Locally regarded as a good beginner or shakeout dive.

Based on community reviews and site data. Conditions vary — always verify before diving.

Best months, historically

What conditions have historically been typical at this site, month by month — not a forecast.

  1. Jan84%5°C0.9 m
  2. Feb82%4°C0.8 m
  3. Mar81%4°C0.9 m
  4. Apr92%7°C0.7 m
  5. May96%11°C0.6 m
  6. Jun96%16°C0.4 m
  7. Jul100%18°C0.3 m
  8. Aug100%19°C0.4 m
  9. Sep93%19°C0.5 m
  10. Oct90%16°C0.7 m
  11. Nov90%11°C0.7 m
  12. Dec88%8°C0.8 m

July and August havetypically had the largest share of favorable days here. Conditions vary year to year — this is historical context, not a forecast.

Based on 3 years of archive data. Bar height shows the share of days each month whose conditions have historically scored favorably.

Marine life seen at this site

Species noted at this site — not a promise of what you’ll encounter.

Species seen here

  • American lobsterCommonly seen
  • Rock crabCommonly seen
  • CunnerCommonly seen
  • Winter flounderCommonly seen
  • Northern sea starCommonly seen
  • Hermit crabCommonly seen
  • Moon snailOccasionally seen
  • Striped bassSeasonal

Fills & rentals nearby

No dive shops mapped within 25 km. Know one? Add it to the map.

Site details

White Horse Beach in the Manomet section of Plymouth is a shallow Cape Cod Bay shore dive centered on Flag Rock, the landmark boulder at the north end of the beach that has carried a painted American flag since 1941. The rocky bottom around the rock holds lobsters and typical New England bay life in roughly 10-30 ft of water - about 35 ft is possible only on the highest tides - making it a good beginner or cobweb-shakeout dive. Average visibility runs around 16-20 ft. Summer parking is the main challenge, with resident restrictions near the beach.

reefshore

Shallow rocky bottom around Flag Rock with surge on onshore (easterly) winds; cold water; summer swimmers; very limited legal parking in season.

Reviews

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