Black Rocks Lagoon - Goat Island & Hauraki Gulf

Double Island might be low on depth, but it’s high on engagement. We love how it feels like a secret garden, a series of rocky fingers and small caves that you can poke your head into. The maximum depth of 10 metres means you get serious bottom time, giving you plenty of opportunity to spot the little things. The visibility here is usually around four metres, which sounds low, but it actually adds to the intimate feel, pushing you to look closer. We've seen New Zealand draughtboard sharks tucked into crevices and banded morwong peering out from the kelp. It’s an easy, interactive dive, perfect for photographers or anyone who likes to take their time exploring the nooks and crannies. You’ll weave through kelp forests, spotting yellow-and-black triplefins and the occasional green rock lobster.

Location
Goat Island & Hauraki Gulf, New Zealand, Australasia
Coordinates
-36.698200, 175.865600
Type
cave
Maximum Depth
5-15m

Marine Protected Area: Rabbit Island

Best Time to Dive in Goat Island & Hauraki Gulf

The warmest water temperatures in Goat Island & Hauraki Gulf occur in February, averaging 22.4°C. The coolest conditions are in August at 14.1°C.

Monthly Water Temperatures

  • January: 21.4°C
  • February: 22.4°C
  • March: 21.8°C
  • April: 19.8°C
  • May: 17.4°C
  • June: 15.3°C
  • July: 14.1°C
  • August: 14.1°C
  • September: 14.7°C
  • October: 16.3°C
  • November: 18.5°C
  • December: 20.3°C

Nearby Dive Sites in Goat Island & Hauraki Gulf

Nearest Dive Centres to Black Rocks Lagoon

Marine Life in Goat Island & Hauraki Gulf

Home to 77 recorded species including 43 reef fish, 11 sharks & rays, 3 whales & dolphins, 3 crabs & lobsters, 3 other, 3 sea snails & nudibranchs.

Notable Species

Recommended Packing List for Black Rocks Lagoon

Based on average water temperature of 18.0°C, currents 2 cm/s.

  • Wetsuit (3-5mm) - comfortable for 18°C water
  • 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

Frequently Asked Questions

What is the typical depth range for diving in Black Rocks Lagoon?
Diving at Black Rocks Lagoon offers a varied depth range. The inner lagoon features a shallow bay, ideal for less experienced divers. For those exploring the outer reef system, dives can reach a maximum depth of 16m.
What kind of marine life and underwater topography can divers expect to see at Black Rocks Lagoon?
Divers at Black Rocks Lagoon can expect diverse underwater topography and marine life. The inner lagoon features a fish shallow bay with plenty of fish and kelp around its edges. The outer reef system boasts impressive "big pins" and nice gullies perfect for swimming through. While standard fish life is present, it's noted that the middle of the lagoon is starting to appear more kina barren than normal.
How challenging is diving at Black Rocks Lagoon, and are there options for different skill levels?
Diving at Black Rocks Lagoon is generally rated as intermediate difficulty, but it truly offers options for all skill levels. The inner lagoon provides a shallow, sheltered bay suitable for beginners and less experienced divers. However, the outer reef system presents a deeper dive that is very exposed to wind, swell, and current, making it more challenging and better suited for intermediate or advanced divers.
What is the best time of year to dive at Black Rocks Lagoon?
Unfortunately, the provided data does not specify the best time of year to dive at Black Rocks Lagoon. For general guidance on seasonal conditions in the region, please refer to our When to Dive section.
What dive certifications are recommended for diving at Black Rocks Lagoon, especially for exploring the outer reef?
For diving within the sheltered inner lagoon at Black Rocks Lagoon, a basic Open Water Diver certification is generally sufficient. However, for exploring the outer reef system, which is a deeper dive and very exposed to wind, swell, and current, an Advanced Open Water Diver certification or equivalent is highly recommended. This will ensure divers have the necessary skills and experience to safely navigate the more challenging conditions.
What are the typical current and weather conditions at Black Rocks Lagoon, and when should divers be cautious?
The outer reef system at Black Rocks Lagoon is notably exposed to wind, swell, and current, which can create challenging conditions. Divers should exercise caution and check local forecasts before planning dives, especially when these elements are strong. Inside the lagoon, conditions are generally calmer, and the average visibility is around 11m.