Chain Islet - Pacific Northwest

We love a good wall dive, and Chain Islet delivers, even if it’s a bit of a local secret. You’ll typically drop onto a sloping reef that quickly plunges into the dark. The real draw here is the sheer number of invertebrates clinging to every surface. Think colossal Dungeness Crabs scuttling across ledges, sidestriped and horned shrimp tucked into crevices, and more nudibranchs than you can count. Our favourite way to dive Chain Islet is to descend slowly, letting your eyes adjust to the green twilight, then slowly ascend along the wall, poking into every overhang. Keep an eye out for Pacific herring baitballs, especially in late summer – when they’re around, you might just spot a harbour porpoise or even an Orca passing through. The visibility can be hit or miss, typical for the PNW, so aim for slack tide on a sunny day if you can. It’s a site that rewards patience and a good dive light.

Location
Pacific Northwest, United States, North America
Coordinates
48.421665, -123.266670
Type
reef
Maximum Depth
8-20m

Marine Protected Area: Lime Kiln Lighthouse 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 Chain Islet

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 Chain Islet

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