Jan’s Tunnel - Poor Knights Islands

Margally is a delightful change of pace in the Somosomo Strait, a spot we often suggest for a relaxed afternoon dive or for getting back into the swing of things after a travel day. It’s got a few coral heads and pinnacles, nothing too dramatic, but they start shallow, just 2 metres, then gently slope down to a sandy bottom around 18 metres. We love the swim-throughs here, they’re not grand caverns, more like playful shortcuts through the coral, and the undercuts always seem to be hiding something. Conditions are usually pretty mellow, making it ideal for newer divers to really take their time. We’ve had some fantastic encounters with Big-spot Anglers camouflaged among the coral, and the Bandcheek wrasse are always darting about. Keep an eye out for nudibranchs, especially around the Montipora and Honeycomb coral. The visibility averages around 13 metres, which is perfectly good for enjoying the busy activity of Scaly Pullers and Deep Reef Chromis. It's also a surprisingly good spot for confident snorkellers who want to explore beyond the immediate surface.

Location
Poor Knights Islands, New Zealand, Australasia
Coordinates
-35.487500, 174.736000
Type
reef

Marine Protected Area: Poor Knights Islands

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 Jan’s Tunnel

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 Jan’s Tunnel

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 maximum depth for diving in Jan's Tunnel?
The maximum depth for diving within Jan's Tunnel is 21 meters, making it accessible for a wide range of recreational divers. The entrance is shallow and perfect for both snorkelers and scuba divers exploring this unique Poor Knights Islands site.
What kind of marine life and unique features can divers expect to see inside Jan's Tunnel?
Divers exploring Jan's Tunnel can expect to encounter various fish life, including demoiselles, snapper, and scorpion fish. However, the site is primarily renowned for its stunning topography and dramatic lighting, which create a truly unique underwater experience. The steep and craggy reef down to 40m also adds to the impressive landscape.
How challenging is the Jan's Tunnel dive site for recreational divers?
The Jan's Tunnel dive site is rated as intermediate difficulty for recreational divers. While the tunnel entrance is shallow and welcoming, the surrounding reef is steep and craggy, extending beyond 40 meters. This offers an engaging experience for divers comfortable with varied underwater terrain.
What is the best time of year to dive Jan's Tunnel for optimal conditions?
Information regarding the best time of year to dive Jan's Tunnel for optimal conditions is not provided in the current data. For general guidance on seasonal diving, you might consult our When to Dive section.
What dive certifications are required to safely explore Jan's Tunnel?
The specific dive certifications required to safely explore Jan's Tunnel are not detailed in the provided information. Given its intermediate difficulty and maximum depth of 21 meters, a standard Open Water Diver certification is typically sufficient for similar sites, but always check with local dive operators.
What are the typical current and visibility conditions like at Jan's Tunnel?
Divers at Jan's Tunnel can typically expect an average visibility of 13 meters, offering clear views of the stunning topography and marine life. Details regarding typical current conditions for this specific site are not provided in the available data.