Post Office Rock - Fiordland

Simpson Rock is one of our favourites at the Poor Knights, a real punchy dive when conditions align. It’s a proper pinnacle, dropping steeply from a tiny patch of rock above the surface down to a platform at about 20 metres. We love to hug the wall, searching for the smaller stuff like Luculentus Wrasse and those tiny Crested Blennies tucked into crevices. Out in the blue, though, is where the drama happens. Schools of New Zealand demoiselle are often so thick they can obscure the light, and when the current is running, you feel every bit of that exposure. It’s the kind of spot where you’re constantly scanning for something bigger, especially in warmer water when Allison's Tuna or even a Blue Shark might cruise by. We’ve seen Red Rock Lobsters here the size of small dogs, too. This site suits divers comfortable with a bit of current and keen to experience the wilder side of the Poor Knights. You'll spend your time circling the rock, either glued to the wall for macro finds or suspended in the blue, watching the constant flow of fish. It’s an exciting dive, best done when the sea isn't too boisterous.

Location
Fiordland, New Zealand, Australasia
Coordinates
-44.580800, 167.792500
Type
pinnacle

Marine Protected Area: Piopiotahi

Best Time to Dive in Fiordland

The warmest water temperatures in Fiordland occur in February, averaging 15.7°C. The coolest conditions are in August at 9.6°C.

Monthly Water Temperatures

  • January: 15.6°C
  • February: 15.7°C
  • March: 15.1°C
  • April: 13.8°C
  • May: 12.4°C
  • June: 10.8°C
  • July: 9.8°C
  • August: 9.6°C
  • September: 10.4°C
  • October: 11.2°C
  • November: 13.3°C
  • December: 14.2°C

Nearby Dive Sites in Fiordland

Marine Life in Fiordland

Home to 49 recorded species including 21 reef fish, 10 sharks & rays, 9 other, 3 whales & dolphins, 3 seagrass & algae, 1 crabs & lobsters.

Notable Species

Recommended Packing List for Post Office Rock

Based on average water temperature of 12.7°C, currents 10 cm/s.

  • Wetsuit (5-7mm) - recommended for 13°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

Frequently Asked Questions

How deep is the Post Office Rock dive site in Milford Sound?
The Post Office Rock dive site has a maximum recommended depth of 18 meters. While the colourful kelpy rocky reef gently drops off to a sandy floor at about 25 meters, divers typically explore the shallower reef areas. This makes it an accessible site for many certified divers.
What marine life and underwater scenery can divers expect to encounter at Post Office Rock?
At Post Office Rock, divers can expect to explore a vibrant, colourful kelpy rocky reef that gently slopes to a sandy floor. The site is abundant with various reef fish, including wrasses, marblefish, tarakihi, dogharks, butterfly perch, and pufferfish. You might also spot octopus and, if you're lucky, the occasional seven gill shark, making for a diverse marine life encounter.
What is the difficulty level of diving at Post Office Rock, and is it suitable for beginner divers?
Diving at Post Office Rock is rated as an intermediate difficulty level. This suggests it may not be ideal for absolute beginner divers who are still gaining experience. Divers should have a comfortable level of skill and experience to fully enjoy the site's features and conditions.
What are the best times or seasons to dive Post Office Rock for good visibility and conditions?
The Post Office Rock dive site offers an average visibility of 11 meters, providing good conditions for exploring its rich marine life. While specific data on the best times or seasons for optimal visibility and conditions is not provided, this average suggests a generally clear diving experience. For general advice on dive planning, you can visit our When to Dive section.
Are there any specific scuba diving certifications required to dive at Post Office Rock?
While no specific certification is explicitly listed for Post Office Rock, its intermediate difficulty level implies that divers should hold at least an Open Water certification. It is always recommended to dive within your training and experience limits, and perhaps consider advanced training for more challenging sites. Always ensure your equipment is in good working order.
What are the typical water conditions and currents like at the Post Office Rock dive site?
The provided data for the Post Office Rock dive site does not specify typical water conditions or currents. However, as an intermediate dive site in Fiordland, New Zealand, divers should always be prepared for varying conditions. It is advisable to check local dive reports or consult with a local dive operator before planning your dive.