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Map of Harbor of Refuge Breakwater (Outer Wall)
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IntermediateBoat entry

Harbor of Refuge Breakwater (Outer Wall)

Delaware, United States
Open Water suggested2–18 m depthBoat entry3mm wetsuit typical

Boat dive — see Entry & access.

Harbor of Refuge Breakwater (Outer Wall) at a glance

Harbor of Refuge Breakwater (Outer Wall) is an intermediate boat dive site in Delaware, United States with depths of 1.5–18.3 m (5–60 ft). Typically most favorable Jul · from 3 years of archive data. Divers commonly see Black drum, Sheepshead, and Blue mussel. Recent reports put the water around 26°C (78°F). Check the latest conditions and entry details before you go.

Marine model · graded 13h ago
0.3 mwaves — under half a meter expected

Tap a factor for its source and model point · Forecast 26°C · seasonal avg 24°C

Site hazards: Tidal currents sweeping the wall, boat traffic entering the harbor, swell wrapping the structure, sharp barnacle- and mussel-covered rocks, fishing line

Read the full hazards ↓

Dive windows this week

Best: Fri
Fri7:00–20:00
Sat7:00–20:00
Sun7:00–20:00
Mon7:00–20:00
Tue7:00–20:00
Wed7:00–20:00
Thu7:00–20:00

Favorable windowModerate window— no window

First light 6:11 · Sunrise 6:38 · Sunset 19:15

Source: Open-Meteo marine · model point 5.1 km from site · graded 13h 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: Blue mussel, Tautog (blackfish)
Best time: Late spring through fall; black drum run is May-June

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. Jan56%4°C0.8 m
  2. Feb58%5°C0.8 m
  3. Mar52%7°C0.9 m
  4. Apr69%12°C0.8 m
  5. May88%18°C0.7 m
  6. Jun89%23°C0.6 m
  7. Jul94%27°C0.5 m
  8. Aug91%26°C0.6 m
  9. Sep92%24°C0.7 m
  10. Oct73%18°C0.7 m
  11. Nov64%13°C0.8 m
  12. Dec63%6°C0.8 m

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 June 2026

Site details

The mile-and-a-half-long outer breakwater off Cape Henlopen, built of more than a million tons of granite in the early 1900s to shelter the mouth of Delaware Bay. The submerged rock slope is heavily encrusted with mussels and attracts tautog, sheepshead, striped bass and record-class black drum, making it the region's storied freediving and scuba spearfishing site; the Gypsum Prince wreck lies at its seaward end. Depths along the wall run from the surface rocks down to about 40-70 ft on the surrounding bottom, with strong tidal flow around the structure.

boatwall

Tidal currents sweeping the wall, boat traffic entering the harbor, swell wrapping the structure, sharp barnacle- and mussel-covered rocks, fishing line

Reviews

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