Cooper Reef - Pacific Northwest

Cooper Reef might not be a household name, but for those of us who dive the Pacific Northwest regularly, it’s a site we always try to fit in. We’re talking about a classic PNW wall dive here, usually done as a drift. Drop in on a slack tide, or just after, and let the current carry you past walls absolutely covered in life. You’ll see sea cucumbers everywhere, the big sweet potato kind, clinging to every surface, and we often spot green and red sea urchins nestled into crevices. Keep an eye out for the resident shiner perch, they hang around in decent schools, and if you’re lucky, you might even catch a glimpse of the roughpatch shrimp. It’s a site that feels wild and untamed. The light can get moody down there, a beautiful, muted green, which really makes the reds and oranges of some of the invertebrates pop. We love hitting this site early on a clear morning, when the surface light still penetrates a bit more. It’s a dive that rewards slow exploration, looking into every nook. If you enjoy a good drift and the unique biodiversity of cold water, Cooper Reef is a solid choice.

Location
Pacific Northwest, United States, North America
Coordinates
48.670918, -123.276750
Type
reef

Marine Protected Area: Kellett Bluff Voluntary No-take

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 Cooper 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 Cooper 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