Poor Knights Islands · New Zealand · Channel & pass · Wall
Middle Arch
An underwater air bubble cave beside drop-offs past 40 metres
Area photo: Anna Barnett · CC BY 2.0
Middle Arch is one of three archways cut through Tawhiti Rahi, the northern island. The bottom under the arch is 14 to 16 metres and PADI rates the site intermediate, but the drop-offs beside it reach 40 metres and more. There is an underwater air bubble cave on the site, and scorpionfish, eels and stingrays are all plentiful on the encrusted rock.
Where it is and how deep
35.4572° S, 174.7326° EPublished position for this site.
The dive
The pass under the arch is comfortable no-decompression diving: the bottom sits at 14 to 16 metres and encrusting life covers the rock on either side of the gap. The oddity of the site is an underwater air bubble cave, a chamber holding trapped air above the waterline that divers can surface into partway through the dive.
Outside the arch the rock keeps going, and the drop-offs here reach 40 metres and more - that is where the intermediate rating comes from, because the shallow part is easy and the deep part is not. Scorpionfish sit against the encrusting growth, eels take the cracks and stingrays are plentiful, and in the right season a manta ray or a bronze whaler shark comes through.
Marine life and season
- Stingrays
- Manta rays
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Prime | Prime | Prime | Prime | Good | Good | Fair | Fair | Fair | Good | Good | Good |
Season follows Poor Knights Islands: The East Auckland Current brings the warmest water and best visibility Jan–Apr; winter (Jul–Sep) is colder with more swell.
Know before you go
- The drop-offs run past 40 metres straight off a 14-16 metre arch, so set a hard depth limit before you go over the edge.
- Archways are where current at the Poor Knights runs hardest, and on spring tides it can be too strong to swim against.
Dive videos
Scuba Diving - Middle Arch - Poor Knights Islands · Scott Rasmussen on YouTube
Questions divers ask
Is Middle Arch suitable for intermediate divers?+
PADI lists it as an intermediate site. The arch itself has a 14 to 16 metre bottom, which is straightforward, but the drop-offs beside it reach 40 metres and more, so the depth of the dive is largely what you make it.
Sources
- Middle Arch dive site — PADI
- Poor Knights Islands — Wikipedia
- Diving the Poor Knights Islands — Wikivoyage
More dive sites in Poor Knights Islands
Schools of blue maomao packed into an eight-metre arch
A 12-15 metre gap over a 40 metre bottom, stacked with stingrays
A large whale jaw bone on the sand at 12 metres, inside the cave
Similar dives elsewhere
A protected colony of endangered grey nurse sharks
Bridge pylons and an 18 m artificial reef, dived at slack or as a tidal drift
Eagle rays and grey reef sharks crowding the channel as the tide floods in
Hook in on the channel edge and let the current run