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Map of Bigelow Hollow State Park (Mashapaug Lake)
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Shore entry

Bigelow Hollow State Park (Mashapaug Lake)

Connecticut, United StatesDirections
Open Water suggested0–12 m depthShore entry

Bigelow Hollow State Park (Mashapaug Lake) at a glance

Bigelow Hollow State Park (Mashapaug Lake) is a shore dive site in Connecticut, United States with depths of 0–12.2 m (0–40 ft). Typically most favorable Jul · from 3 years of archive data. Divers commonly see Brown bullhead, Crayfish, and Smallmouth bass. Check the latest conditions and entry details before you go.

Wind model · graded 14h ago
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Tap a factor for its source and model point

Site hazards: Boat traffic near the ramp, long gear carry, cold water below the thermocline, low visibility

Read the full hazards ↓

Dive windows this week

Best: Sun
Fri7:00–20:00
Sat7:00–20:00
Sun9:00–20:00
Mon9:00–19:00
Tue7:00–19:00
Wed10:00–19:00
Thu7:00–14:00

Favorable windowModerate window— no window

First light 5:56 · Sunrise 6:24 · Sunset 19:05

Source: Open-Meteo wind · graded 14h 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.

Dived here today — did the forecast match?

What Divers Say

Known for: Crayfish, Smallmouth bass, Yellow perch
Best time: Summer and early fall mornings before boat traffic

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. Jan74% 11 kn
  2. Feb81% 11 kn
  3. Mar72% 12 kn
  4. Apr87% 11 kn
  5. May87% 10 kn
  6. Jun96% 9 kn
  7. Jul97% 8 kn
  8. Aug96% 8 kn
  9. Sep93% 8 kn
  10. Oct91% 9 kn
  11. Nov81% 11 kn
  12. Dec77% 10 kn

July hastypically 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

Fills & rentals nearby

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

Data updated July 2026

Site details

A designated scuba area on Mashapaug Lake inside Bigelow Hollow State Park in Union, one of the few Connecticut state park waters that formally permits diving. The dive access is a small cove about a quarter mile from the Mashapaug Lake boat ramp, over a rocky and sandy freshwater bottom with a maximum depth around 40 feet.

shore

Boat traffic near the ramp, long gear carry, cold water below the thermocline, low visibility

Reviews

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