Northern quarter of the Poor Knights Islands.
Note that the first three depth contours are for 10, 20 and 30m depth.
Wild Beast Point Wild Beast Point is the northernmost tip of the Poor Knights, so named
because of the bronze whaler sharks frequenting this area in summer. It
is a place where the island splits the current, a cauldron of turbulence
and wild water, and therefore seldom dived at. But underneath extends a
sloping kelp platform that on the western side drops away in a steep abyss.
This side is most interesting because of its relative shelter and strong
currents.
Boats cannot anchor here and need to idle around, waiting for divers to
return to the surface. Small boats can anchor on Ann's Rock, from where
one can swim against or with the currents. Make sure you can make it back,
even if the current changes.
Wild Beast Point is where shoals of fish swim into the nourishing current,
alternatively seeking refuge in the relative shelter of Maomao Bay. Maomao
Bay is deep (70m) with large boulders rising to 40m, and it offers excellent
sleep-outs for the numerous pink maomao found here.
f216602: Wild Beast Point seen from the east. In front is
a sloping platform over which the swell rises to colossal heights. Notice
the very high grey splash zone. Not a nice place to dive.
f216603: Wild Beast Point, seen from the north towards Northern
Arch, in the middle of the picture. On this side one can dive a picturesque
wall, surrounded by countless plankton eating fishes. It is a tricky dive.
f042712: on the wall one finds a rich community of golfball
sponges and yellow antler sponges, and beadlet coral, a gorgonean.
f048724: the pink maomao here find divers an interesting
diversion, as they come up slowly from the deep to investigate.
Ann's Rock Maomao Bay is deep and its walls sheer, with a single rock poking up
alongside a steep wall (named after Ann Roberts, married to fish scientist
Clive Roberts). Almost impossible to anchor outside the surging swell,
Ann's Rock is accessible only during very calm seas. The rock itself has
no redeeming features: a monotonous expanse of strapweed and stalked kelp.
Northern Arch Northern Arch is a geological impossibility: a strictly parallel cleft
through a rocky promontory, 6-8m wide and 40m tall. How can that be explained?
The promontory stretches out westward across the current, and not surprisingly,
the currents can run swiftly through the archway and around the promontory.
Boats knowing the locality well, anchor carefully on some of the large
boulders that rise up from a 70m deep bay, as an anchor is too easily lost.
Thus most diving is done from the northern side, and this is possible only
when shelter prevails. When done from the southern side, also Cattons Cave
can be explored.
A word of caution The Northern Arch is a spectacular dive but also one
of the most dangerous ones. Already a dozen divers have lost their lives
here, a fact that is hushed up because dead divers are not good for business.
So what should one do? There are these aspects of danger:
Most visiting divers have had their training in warm tropical
seas with light wetsuits and light weight belts. Here in NZ you will wear
a 7mm wetsuit with 10-14kg of weight on your belt. That means that you
have a correspondingly large air bubble of 10-14 litres around you, and
this air becomes compressed, making you heavier. For the first ten metres
you become 5-7kg heavier. At 30m depth you are 8-12kg heavier. To compensate,
you will inflate your buoycomp, and usually too late, when you already
begin to fall. Conversely, you deflate too late, resulting in a deadly
rapid ascent. You MUST be compensating your buoyancy ALL THE TIME! When
in trouble, hold on to the rock or stalked kelp.
Most visiting divers do not have adequate physical fitness.
Here you are diving in a truly open sea, with waves and currents. It is
strenuous and you can easily get into trouble. Make sure that you swim
against the current on the way out, in order to return with the current
on the way back. Most importantly, swim from the boat to the wall first.
Then come to rest before going down. It may take a few minutes, well spent.
The bottom is deep and the walls sheer. You cannot easily
find a ledge to rest on. So make it a habit to hold on to a kelp stipe
until you are completely rested and evened out.
The current in Northern Arch can be unpredictable and also
strong. Make sure you proceed with care.
The bottom of the Arch is deep and you can too easily end
up there (36-40m).
Northern Arch is not suitable for night diving.
f012701: Northern Arch seen from its northern side. Boats
usually anchor on the left margin of the picture. From there it is a 30-40m
swim to the archway, with rich seascapes in between.
f048733: a caleidoscope of coloured fish: red-orange golden
snapper, pink maomao, blue maomao, blue and green two-spot demoiselles
and grey porae. Nowadays even large snapper can be encountered.
One of the widely plublicised attractions of the Northern Arch is the
presence of a large number of sting rays, apparently swimming around aimlessly.
Much has been speculated about why they are there: pre-mating behaviour,
socialising, playing and more. But they have not always been doing this,
as it began some time around 1990, as observed by myself. And in recent
times, their numbers have declined sharply. So what is going on? Read more
about The Mystery of the
social stingrays of Northern Arch. For the lucky visitor,
the stingrays are either hovering in one place or slowly flapping around,
while taking little notice of divers. Don't be afraid, as they skillfully
dodge you, if even by a few centimetres only.
f011933: a few short-tailed stingrays (Dasyatis brevicaudata)
in Northern Arch. The white one is an albino.
f011933: a rare photo taken with a 50mm lens, showing 24-26
stingrays in a single image. The white one is an albino.
f020537: young demoiselles bunched up to the margin of the
cave's shadow in order to remain invisible to marauding gannets.
f024134: Northern Arch can be spectacular for its large blue
maomao schools, who come here for a rest.
f020516: at 40m depth, the rocks are covered in sessile filterfeeders
like these beadlet corals and golfball sponges.
f024116: on the bottom at the northern side of the Arch is
a bronze plaque in memory of John Catton, one of the early explorers of
the Knights.
f020517: "In memory of John Barrie Catton aged 26 yrs. Lost
at Cattons Reef 1.8km north of this (Tawhiti Rahi) island on 4th August
1979. At the frontiers of endeavour, perils abound. Moderate exertion at
the surface can be fatal at depth." John Catton disappeared on a very deep
reef NE of the Poor Knights.
f020511: ten short-tailed stingrays hovering inside Northern
Arch. At the best of times I counted 53. Read more about what they are
doing in The mystery of the
social stingrays.
f048708: as currents veer along the promontory, a rich community
of filter-feeding fans can be found no deeper than 30m.
f042717: beadlet gorgonean fans and demoiselles passing by.
Catton's Cave Named after veteran explorer/diver John Catton, this small cave is
found in a corner where the promontory joins the northern island. From
the outside hardly visible, it is a vertical slit that can be entered.
Once inside, the slit rises all the way to the surface and ends in a pool
of brown fresh water. The cave is a hideout for groupers such as the yellow
banded perch and black spotted groupers, now rare on the Knights.
Cleanerfish Bay An uneventful stretch of coastline stretches between Northern Arch
and Middle Arch and is called Cleanerfish Bay. Although not frequently
dived, it provides some good divable habitat with enough variation and
pinnacles worthy of exploration. At least the blue maomao schools one finds
here, think so.
f013005: a giddying sight, schools of surface-feeding blue
fish in a translucent blue sea.
f013003: the moment of whoosh when they all decide to dive
down.
f042610: good diving can be had in Cleanerfish Bay, from
very shallow seaweed gardens, to convenient depths. A snorkeldiver is observing
a gathering of fish.
f042627: a snorkeldiver swims over a knoll with green sea
rimu (Caulerpa brownii) and red seaweeds.
Middle Arch Contrary to Northern Arch, Middle Arch is in every way a safe place
to dive: it is more shallow with only weak currents and it has shelves
that one can rest on in case of emergency. Middle Arch is a gold mine for
macro photographers and marine ecologists because the merging of habitat
boundaries causes unexpected biodiversity, variation and change.
Most divers will begin at the southern entrance, enter Bernie's cave, go
through the archway, veer left and around the promontory and back to the
boat. It is a very nice dive, crossing many habitat zones while seeing
a high diversity in fish and other species. Around the promontory there
will be some current and much schooling fish. Photographers will most likely
stay around the southern entrance and Bernie's Cave for its many outstanding
macro opportunities.
If you wish to see the deep reef, stay on the shaded side, left of the
southern entrance and go down to 30m, where the beadlet gorgoneans are
within diving range. You will also see a good selection of colourful sponges
and other cliff dwellers.
f020336: the northern entrance to Middle Arch descends steeply
to 50m near the bottom of the photo. On right the western wall with behind
the far entrance, Bernie's Cave.
f020500: a dive charter boat is arriving for Middle Arch
and will anchor at the southern entrance over 23m depth. Bernie's Cave
is where the nick is at the left side of the Archway, just in front of
the ship's bow.
f029907: the western wall is the most sheltered place of
the Poor Knights, with a current. One finds these gorgonean fans no deeper
than 5m. In between grow fragile bryozoan bushes, grazed upon by rare Tambja
nudibranchs.
f034921: a view of the riotous life just above Bernie's Cave,
at the archway's most sheltered wall.
f043213: the eastern wall is more exposed, yet covered in
an unusual variety of life, often with unusual species. These sponges grow
right under the surface!
f024014: near the bottom, the archway becomes more barren.
In the photo a pair of Lord Howe Island coralfish.
f024206: Also the western wall becomes more barren towards
the bottom. Here a school of young blue maomao is sheltering where the
water moves least. Just behind the school is the entrance to Bernie's Cave.
Bernie's Cave Bernie's cave (named after professional diver Bernie Keegan) is a safe
cave because it is close to the surface, not deep inside, and its opening
is very wide. At the top of the cave is an air bubble with enough space
above it to take a breath and to talk. In the photo below, you can see
the diver's light penetrating the bubble and at the top of the photo you
can see the rock inside the bubble. Divers think that the air bubble is
caused by diver's air but most of the air comes from tiny air bubbles produced
by waves during storms. Through the water's surface, the air in the bubble
is refreshed in the periods between diver visits.
Inside the cave one can see the life petering out as planktonic food becomes
scarce towards the end. That is perhaps also the reason that two statues
placed there, only slowly become fouled by encrusting life. Pay attention
to the cave entrance, which is very rich, all the way to the surface. Here
you can also find rare sea slugs. In the very back of the cave often the
shy rock cod (Lotella Rhacinus) can be found.
f024006: a diver enters Bernie's Cave, completely mirrored
in the air bubble above.
f024010: someone placed this little green frog here. Does
anyone know the story? e-mail me.
f029723: and someone placed this little bear here, now being
covered by little red seasquirts. Does anyone know more?
f019622: yellow zoanthid anemones thrive in the shelter of
Middle Arch.
f029121: close-up of yellow zoanthid anemones.
f029404: in the shelter and darkness of the Arch, delicate
life forms thrive such as these red hydroid firs. The green-lined tambja
nudibranch is specialised in feeding on these little polyps.
f029424: a greenish morose tambja (Tambja morosus)
feeds on the tiny polyps of bushy bryozoa like the orange tufts on bottom
right and the stick bryozoa on left.
Cream Gardens The cream gardens are marked by a large square cave above the water
(see photo below). With some difficulty one can anchor there in 15-30m
depth but very often this place cannot be dived because of heavy swell.
By swimming out along the promontory and diving down the cold upwelling
to 30m, along a most spectacular wall, then towards the end of the dive
spending time swimming back at 6-8m depth while decompressing and hopefully
encountering some most spectacular bronze whaler sharks. These fish are
very shy but stunningly beautiful. Imagine a golden shark with a white
belly, no larger than 3m. In this area there is also a lot of fish, both
in open water and on the fiercely moving seaweeds. Here the swell races
up a ramp that could catch you unaware, so stay away from the shallows
and from white water.
f216601: looking north to Wild Beast Point in the distance
and a small promontory almost invisible right of the cave. Just to the
right of this point extends a long and very deep vertical wall, which is
rich in sessile life.
f041806: at its southern end, the wall ends suddenly, sending
cold water up to the very surface. In this junction pink maomao find shelter
to rest and sleep. Upwellings like these feed fish further south.
f038732: towards the top edge of the wall one finds the more
sturdy cliff dwellers. A large yellow boring sponge is being invaded by
yellow zoanthid anemones. Kelp can just grow here but not further down.
f038731: deeper down one finds bushy bryozoa of several kind,
and gorgonean fans. The kelp in the distance is scruffy and does not thrive
at this depth and darkness.
f041818: semi-pelagic fish that catch their food in open
water but return to the rock at night, are found resting here. The pink
fish are a male and female butterfly perch. Males have a green iridescent
patch above their eyes.
Barren Arch As its name suggests, Barren Arch is indeed mainly barren. There have
been attempts to rename this arch more politically-correctly (Splendid
Arch), but this is wrong because Barren Arch could well be the worst hell-hole
in New Zealand. We spent an entire page (The
mystery of Barren Arch) explaining why, which is very interesting.
It is a unique place if only you knew why.
But here is the short of it: during really big storms arriving from the
north-east, the steep wall reflects and focuses waves into barren arch
where they run up a ramp while accelerating to perhaps hundred kilometres
per hour. This velocity moves one ton bricks as if they were autumn leaves,
through the cave and up the ramp and out at the other end !!!!! Boulders
that do not quite make it, roll back through the two deep grooves at the
sides of the ramp. Quite unbelievable, but the solid evidence is there.
So once in a while, Barren Arch is scrubbed clean, and only in the relative
calm in between, can life reestablish itself somewhat. We haven't had a
big tropical cyclone for a long time, so it seems that the arch is no longer
so barren - just wait.
Diving Barren Arch is possible only after a long calm and westerly winds,
so that the easterly swell has died down. Boats will anchor in the shallow
part of the northern cove. Divers can then enter the cave the long and
safe way, swimming south along the outside to the 40m deep entrance, or
the more adventurous way, going over the ledge at its shallow northern
end - quite daunting but possible at high tide.
f012536: a yacht in the southern cove is dwarfed by the steep
rock wall that extends steeply under water. Storm waves are reflected by
this parabolic wall, and focused onto Barren Arch.
f012537: this photo joins the one to the left as in a panorama,
showing the deep entrance to Barren Arch. A small boat can enter and turn
inside, but cannot pass the far end.
f024911: during ordinary weather conditions, the cave provides
shelter to schools of fish like this small school of pink maomao. In front
a mado. Notice the barren rock on left, and debris in the debris gully.
f024914: a diver finds a large umbrella slug on the high
ground (berm) between the ruts. On left the rut (debris gully) through
which boulders roll. On right the higher middle ground with much more life.
f024918: in the lull between major storms, sensitive life
returns to the cave like these golfball sponges and an unknown grey sponge.
f024910 (left photo): at the shallow end, the walls of
the archway have been ground barren to several metres above the deep rut.
There is a sharp boundary marking where the last storm ground all the life
off. The wall feels almost like polished, and is covered in a pallet of
velvet carpet sponges.
f024915 (photo above): detail of the band of life that was
spared during last storm, above the band of carpet sponges.
f024916: these mature sponges show that in some places, life
has been spared for some fifty years. The grey sponge is Ancorina alata
and the orange sponge a crater sponge Stelletta crater without crater.
Notice how life peters out towards the deep groove far left.
Macro city more information needed
Cave Bay Cave Bay is a deep cove exposed to the worst of storms, but it has
a rising staircase of large bricks that are doing a good job of absorbing
wave energy, to such extent that at the very end a beautiful seaweed garden
can be found, attractive for snorkellers, while its northern wall provides
good night diving deeper than 10m, with an abundance of sensitive life
forms.
f048604: seaweed gardens at Cave Bay, with stalked kelp in
foreground and strap kelp in the background.
f048609: snorkeldiver and strap kelp (Lessonia variegata).
f048625: snorkeldiver and tall zigzag weed (Cystophora
sp.), and a variety of other seaweeds in the background.
f048616: a black angel fish (Parma alboscapularis)
parading its territory, but no edible seaweeds in this photo. The red fretsaw
weed () in the foreground and the tough small-leaved wire weed (Carpophyllum
angustifolium) in the background.
f052535: a scalyheaded triplefin (Karalepis stewarti)
on orange sponge and jewel anemones (Corynactis haddoni). A night
dive along the northern wall does not encounter gorgonean fans but a plethora
of more robust cliff dwellers.
f052507: hardy jewel anemones (Corynactis haddoni)
thrive in rough conditions.
f052504: cup corals (Flavellum rubrum, Momomyces rubrum)
extending their tentacles far out in the turbulent waters.
