Hagen Reef - Pacific Northwest

The Seven Stones Reef sits out there, a real wild card in Cornish diving. It’s not your usual accessible shore dive; this is one you plan for, often by boat from somewhere like Sennen Cove, weather permitting. The conditions can be… lively, so you’ll want some experience under your belt. What we love about the Seven Stones is that untamed feeling. Descending onto the rock formations, it’s a mosaic of colours from the jewel anemones and Devonshire cup corals that coat every surface. It’s a good spot to see larger pelagics too. We’ve had Short-beaked Common Dolphins zip past us here, and the gulls - Kittiwakes, Great Black-backed Gulls - are always wheeling overhead, a reminder of how remote you are. Keep an eye out for the Glycerine Worms; they’re surprisingly beautiful against the dark rock. Visibility can vary wildly with the tides and swell, but on a good day, it’s truly something. This site suits adventurous divers who appreciate raw, exposed reef diving.

Location
Pacific Northwest, United States, North America
Coordinates
49.208370, -126.083990
Type
reef

Best Time to Dive in Pacific Northwest

The warmest water temperatures in Pacific Northwest occur in August, averaging 16.5°C (up to 15.6°C). The coolest conditions are in February at 6.9°C.

Monthly Water Temperatures

  • January: 7.1°C (air: 6.3°C)
  • February: 6.9°C (air: 4.5°C)
  • March: 7.7°C (air: 6.6°C)
  • April: 9.5°C (air: 8.7°C)
  • May: 12.0°C (air: 11.7°C)
  • June: 14.0°C (air: 13.7°C)
  • July: 15.7°C (air: 14.9°C)
  • August: 16.5°C (air: 15.7°C)
  • September: 14.3°C (air: 14.0°C)
  • October: 11.4°C (air: 10.5°C)
  • November: 8.8°C (air: 7.4°C)
  • December: 7.7°C (air: 5.5°C)

Nearby Dive Sites in Pacific Northwest

Nearest Dive Centres to Hagen Reef

Marine Life in Pacific Northwest

Home to 38 recorded species including 18 reef fish, 7 crabs & lobsters, 3 whales & dolphins, 2 sharks & rays, 2 clams & mussels, 2 sea urchins.

Notable Species

Recommended Packing List for Hagen Reef

Based on average water temperature of 11.0°C, currents 7 cm/s.

  • Wetsuit (5-7mm) - recommended for 11°C water
  • Hood & Gloves (3-5mm) - helps retain warmth
  • Mask - essential for every dive
  • Fins
  • BCD - buoyancy compensator
  • Regulator - your most safety-critical piece of gear
  • Dive Computer - tracks depth, time, and NDL
  • Surface Marker Buoy (SMB) - essential for boat pickups
  • Dive Torch - useful for crevices and colour at depth
  • Underwater Camera - capture your diving memories