Gem Cave - Poor Knights Islands

La Marado on Moorea is one of those sites we always try to hit, especially if the conditions are playing nice. It’s got that dramatic topography that makes for an interesting dive, with chimneys and a distinctive peak we call Oti Point. Drop down and you’re looking at healthy corals, a real mix of branching stuff and big plates, then you start seeing the fish. We often spot schools of Blackfish swirling in the channels, and there’s a good chance of finding Parrotfish, particularly Schlegel's, browsing the reef. Keep an eye out for those tricky-to-spot Bluefin Filefish tucked into crevices. What we really love about La Marado, besides the always-excellent visibility that generally hits 25m, are the canyons. Towards the end of the dive, you can cruise through these natural cuts in the reef, which is a surprisingly refreshing way to finish things off. It’s a great site for divers who appreciate interesting reef architecture and a solid mix of reef fish, rather than just chasing the big stuff. Max depth is 27m, so it’s accessible to most certified divers without getting into technical territory.

Location
Poor Knights Islands, New Zealand, Australasia
Coordinates
-36.266000, 174.799500
Type
reef
Maximum Depth
5-15m

Marine Protected Area: Cape Rodney-Okakari Point

Best Time to Dive in Poor Knights Islands

The warmest water temperatures in Poor Knights Islands occur in February, averaging 21.9°C. The coolest conditions are in August at 15.8°C.

Monthly Water Temperatures

  • January: 21.4°C
  • February: 21.9°C
  • March: 21.7°C
  • April: 20.6°C
  • May: 19.1°C
  • June: 17.6°C
  • July: 16.5°C
  • August: 15.8°C
  • September: 15.9°C
  • October: 16.6°C
  • November: 18.2°C
  • December: 19.8°C

Nearby Dive Sites in Poor Knights Islands

Nearest Dive Centres to Gem Cave

Marine Life in Poor Knights Islands

Home to 84 recorded species including 53 reef fish, 11 sharks & rays, 4 whales & dolphins, 4 other, 3 crabs & lobsters, 2 sea urchins.

Notable Species

Recommended Packing List for Gem Cave

Based on average water temperature of 18.8°C, currents 12 cm/s.

  • Wetsuit (3-5mm) - comfortable for 19°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 maximum depth for recreational diving within Gem Cave?
The typical maximum depth for recreational diving within Gem Cave is 9 meters. This makes it a relatively shallow dive, suitable for most certified divers.
What kind of unique geological formations or marine life can divers expect to encounter in Gem Cave?
Divers exploring Gem Cave can expect to encounter a unique geological formation with two entries that merge at the back, featuring a slight space between the surface and the cave ceiling. The walls, initially dim, reveal many vibrant colors when illuminated with a torch. Marine life includes sponges, anemones, nudibraches, shrimp, big eyes, and crabs, making for a colorful display.
How challenging is the Gem Cave dive site, and is it considered suitable for advanced open water divers or only certified cave divers?
The Gem Cave dive site is rated as intermediate in difficulty. Given that it doesn't go far back and maintains a slight space between the surface and the cave ceiling, it is generally considered suitable for experienced open water divers rather than requiring specific cave diving certifications.
What is the best time of year to dive Gem Cave for optimal visibility and water conditions?
While Gem Cave is best dove during high tide, the provided data does not specify a particular time of year for optimal visibility or water conditions. Divers can generally expect an average visibility of 8 meters. For more general information on seasonal conditions, please refer to our When to Dive section.
Are there specific scuba diving certifications, beyond standard open water, required to explore Gem Cave?
Based on its intermediate difficulty and the presence of a slight space between the surface and the cave ceiling, specific cave diving certifications are not explicitly required to explore Gem Cave. It is generally suitable for experienced open water divers comfortable with cavern-like environments.
What are the usual current conditions and water temperatures like inside Gem Cave?
The provided data for Gem Cave does not include specific information regarding usual current conditions or water temperatures inside the cave. Divers should consult local dive operators for the most up-to-date environmental details.