Aldermens- Bishops Hat - Goat Island & Hauraki Gulf

Bishops Hat, out in the Aldermens, is a fantastic spot we always try to hit when the weather cooperates. It’s exposed to those easterlies and south-easterlies, so pick your day carefully, but when it’s good, it’s *really* good. We love dropping in here, particularly for the cave. It’s not a deep dive, peaking around 17 metres, but the way the light filters in through the entrance is just captivating. Inside the cave itself, we’ve often seen big Rig sheltering, and the walls are plastered with these colourful bristleworms that really catch your eye. Our favourite part has to be the outside wall though, where the kelp gives way to deeper water. This is where you might catch a flash of California Yellowtail or even a cruising Blue Shark if you’re lucky. We always keep an eye out for the cheeky New Zealand Draughtboard Sharks tucked into crevices. Visibility averages around 21 metres, which for New Zealand, feels like a gift. If you’re into a gentle drift, exploring some interesting rock formations, and don’t mind a bit of a boat ride, Bishops Hat is a winner. It’s a great dive for anyone comfortable with a bit of current and keen to see what the Hauraki Gulf really has to offer beyond the usual spots.

Location
Goat Island & Hauraki Gulf, New Zealand, Australasia
Coordinates
-36.953400, 176.101900
Type
cave
Maximum Depth
10-30m

Marine Protected Area: Wharekawa Harbour Wildlife Refuge

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 Aldermens- Bishops Hat

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 Aldermens- Bishops Hat

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 are the typical diving depths at the Aldermen Islands dive site?
The Bishop's Hat dive site, located near Goat Island, offers a maximum depth of 17m. This makes it suitable for a range of divers looking to explore its diverse features, including a cave and a wall.
What kind of marine life and underwater features can divers expect to see at the Aldermen Islands?
At the Bishop's Hat dive site, divers can explore fascinating underwater features including a cave and a wall. The site is renowned for its marine life, with frequent sightings of big kingfish and crayfish, alongside various common New Zealand fish. For more on marine species, visit our wildlife database.
How challenging is diving at the Aldermen Islands, and are there sites suitable for beginners?
Diving at the Bishop's Hat site near Goat Island is rated as intermediate difficulty. While the specific site offers a cave and wall, it is generally not recommended for absolute beginners due to its intermediate rating. Divers should have appropriate experience for these conditions.
When is the best time of year to dive the Aldermen Islands for optimal conditions and marine encounters?
The provided information for the Bishop's Hat dive site does not specify a best time of year for diving or seasonal marine encounters. However, it notes the site is exposed to weather from the east and south-east, which might influence dive planning. For general guidance on dive seasons, you can check our When to Dive section.
What scuba diving certifications are required or recommended to dive at the Aldermen Islands?
While specific certification requirements are not explicitly stated for the Bishop's Hat dive site, its intermediate difficulty rating suggests that divers should possess at least an Advanced Open Water certification or equivalent experience. This ensures you are comfortable with the conditions and features like caves and walls. Always consult with local dive operators for their specific requirements.
What are the typical water conditions and currents like at the Aldermen Islands dive site?
Divers at the Bishop's Hat dive site can typically expect excellent visibility, averaging around 21m. The site is noted to be exposed to weather from the east and south-east, which can influence surface conditions. While specific current information isn't detailed, divers should always be prepared for varying conditions in exposed areas.