Sea cucumbers

Dive sites: Atlantis Reef

One of the pinnacles of Atlantis Reef rises to near the surface

Atlantis Reef was discovered in September 2011 by Steven Benjamin of Animal Ocean. The site was named for the lost city which is (according to legend) submerged now, but was also known as the Pillars of Hercules prior to its rediscovery by Animal Ocean. Atlantis comprises two massive pinnacles that rise to within 4-5 metres of the surface, along with a jumbled collection of enormous boulders strewn about their base. We dived the site in mid-October, in conditions of almost top to bottom visibility. The topography of the site is breathtaking – huge, vertical walls and enormous rocks distinguish it from the lower rocky reef characteristics of the Roman Rock area. The sand lies at about 30 metres on the seaward (eastern) side of the reef, but the average depth is about 20 metres. With a large cylinder full of a nice Nitrox mix, you could dive here for days (water temperature permitting).

Tony over the giant arrowhead (pointing towards the top of the photo)

Fissures in the granite of the reef provide homes for fish

Huge boulders stacked one on top of the other

Massive granite boulders characterise the site

Visibility was almost top to bottom when we dived Atlantis

Lower down on the pinnacle, more sea fans and invertebrates appear

The side of the inshore pinnacle, near the surface

Redbait and urchins cover the tops of the pinnacles

Kelp in the shallow water on top of the pinnacle

Kelp growing on top of the shallower pinnacle

Fish above the redbait that crowns the pinnacles

View from above of the top of the inshore pinnacle

Cape rock crab hiding among the redbait on top of one of the pinnacles

We dropped right on top of the pinnacle closest to shore, and the boat skipper hadn’t used a shot line for fear of damaging the pristine and hardly dived reef. Tony and Justin went down to the sand in order to do a compass swim for Justin’s Deep Specialty course, and I hovered next to one of the pinnacles. The pinnacles are about 3 metres across on their tips, but widen out to a large, roughly rectangular base on the sand. Between the pinnacles is a large overhang, and large cracks in which we saw congregations of janbruin. We spotted some very large (more than 30 centimetre long) zebra and Roman between the pinnacles, as well as some white seacatfish also enjoying one of the cracks in the rock. I discovered some fascinating facts about Roman this week, but they can wait…

Massive school of hottentot, fransmadam and other fish

Fish feeding among the redbait on top of one of the pinnacles

To me, the most spectacular feature of the marine life on the reef is the large schools of fish that assemble around the pinnacles. The reef lies within the Castle Rocks Protected Area and no fishing is allowed there, and it obviously hasn’t been discovered by the fishermen – both commercial and amateur – who don’t care about protected areas and enjoy the fact that they aren’t policed at all. Hottentot, fransmadam, and zebra mill around in their hundreds – I have never seen a school of fish like this in the Cape. The strepies at Long Beach last summer were – until now – the most prolific fish I’ve seen here. The fish are quite relaxed and just reshaped their school around the divers.

Anemones, urchins, corals and sea fans cover the upper reaches of the pinnacles

A knobbly anemone among sea fans, sea cucumbers and other invertebrate bounty

There are also the usual sea fans (plus what looked like a nursery for baby sea fans), massive nudibranchs of several varieties, sea cucumbers, anemones, and a lot of other invertebrate life. The top parts of the pinnacles are covered with huge redbait, interspersed with Cape urchins and several varieties of sea anemone. Lower down on the pinnacles we found orange wall sponges and other sponge species, as well as large klipfish trying to camouflage themselves against the wall.

There was some interesting discussion about whether it is right to have an “exclusive” dive site that only you know the co-ordinates to. An argument was put forward that when one finds a pristine spot like this, it’s natural to want to protect it from careless, ignorant or inexperienced divers. Hopefully the boat charters – all of whom now know where this reef is – will put aside financial considerations when taking divers to this reef, and only allow divers who they know can manage their buoyancy and don’t engage in behaviours that are detrimental to the marine life of the locations they dive. Whether this happens will remain to be seen. (I, for one, am not optimistic… Enjoy it now, while it lasts.)

Dense invertebrate life on the pinnacles

Knobbly anemone (right) on Atlantis Reef

A red sea star among coraline algae and strawberry sea anemones

A sea star gets a grip and holds on tight

Shyshark resting inside an orange wall sponge

I want to go back to this site tomorrow, or yesterday if that’s possible. I’ve been (irritatingly) ranting about it to whoever will listen since we dived it. It’s wonderful to me that we are still finding new places to dive in our local bay of plenty, and so close to shore, too! Also, seeing how healthy and abundant the fish that call this reef home are, I’m thrilled that (it seems) the Marine Protected Areas are working, despite hopelessly inadequate support from the authorities. It made me so, so happy to see this reef. Can’t wait to go back!

Tony swims past the top of one of the pinnacles

Dive date: 15 October 2011

Air temperature: 19 degrees

Water temperature: 13 degrees

Maximum depth: 21.5 metres

Visibility: 15 metres

Dive duration: 40 minutes

Dive sites: Roman’s Rest

Roman Rock lighthouse stands near the entrance to the navy harbour in Simon’s Town. In its general (I use the term very loosely) vicinity one finds – amongst other sites – Tivoli Pinnacles, Castor Rock, Wonder Reef, Rambler Rock, and, of course, the Roman Rock reef system, which is right under and around the lighthouse. Grant didn’t drop the shot line right at the lighthouse as one would to dive Roman Rock itself, but at a set of pinnacles called Roman’s Rest which are at the eastern end of the Castor Rock reef complex. Wonder Reef is at the western end.

A flagellar sea fan swaying in the surge

Tami and I agreed that this was one of the most beautiful dive sites we’ve visited in False Bay – it’s comprised mostly of large granite boulders and huge flat, sloping rocks that are rich with invertebrate life. The whole area is populated by various types of sea fan, giving the effect of an underwater forest.

Close-up of the branches of a flagellar sea fan

Flagellar sea fans, cauliflower soft coral, and a palmate sea fan

Close up of a palmate sea fan's branches — Close up of a palmate sea fan’s branches

Lots of cauliflower soft coral on top of the reef

I was a bit cold (it was the second dive I did that day, and I had not put on enough layers of wetsuit to compensate for the freezing boat rides to and from the sites!) so I didn’t manage any half-decent photos of fish. But we saw Roman (of course!), and a large school of hottentot or other nondescript silver fish hanging in midwater over the reef. There were many nudibranchs – contrary to our usual experience of seeing one at a time, we saw several that were often so close together that I could include them all in one photo.

Sea fans stand like small outcrops of trees over the reef

The part of Roman Rock that we dived is a newish area, I think, that Peter Southwood is busy mapping for the Diving the Cape Peninsula and False Bay wikivoyage site. It’s a very, very special site – highly recommended. With the right equipment and good visibility, lovely wide-angle photographs can be possible.

There are a couple more pictures from this dive in the newsletter Tony put out in the week after we dived the site. The surface conditions were horrible but you can see that the visibility was very good indeed (by False Bay standards!).

Ascidians in the (shallower) red bait zone

Fish schooling in midwater above the reef

Two silvertip nudibranchs flank a blue gas flame nudibranch

Dive date: 27 August 2011

Air temperature: 19 degrees

Water temperature: 14 degrees

Maximum depth: 21.4 metres

Visibility: 10 metres

Dive duration: 42 minutes

Floating egg ribbon (?) at the safety stop

Dive sites: SAS Pietermaritzburg

I’ve dived the SAS Pietermaritzburg once before, as part of the Wreck Specialty course I did along with Tami and Kate. The water then was distinctly green, and I was armed with a slate trying to draw a plan of the vessel. My other hand was trying to take photographs of nudibranchs. I didn’t perform either task particularly well.

The interior of the wreck is visible through the deck

The metal of the deck is very buckled in places

Looking down off the wreck at some bollards

Heavily encrusted remains of the gunwales

Tony investigates the bow of the SAS Pietermaritzburg

There's brass under the urchins and sea cucumbers... — There’s brass under the urchins and sea cucumbers…

Lovely rusty deck plates with rivet holes

Tony and I dived the Pietermaritzburg again on 9 July, as part of the OMSAC Treasure Hunt. We were on the Dive Action boat, and they dropped anchor on the wreck so the boat was over us throughout the dive. While I’m not sure about dropping shotlines and anchoring directly on wrecks, it’s universally practiced in Cape Town and does give a sense of security when one surfaces (assuming you’ve managed to stay on the dive site!).

The Pietermaritzburg was scuttled in 1994. She’s an old minesweeper, and actually participated in the D-Day invasion of Normandy as the lead minesweeping vessel. Having this little piece of history right in False Bay is quite awe-inspiring, particularly to someone like me who gets quite weepy (literally) if you mention the war. She was sold to the SA Navy in 1947, and was used as a training vessel and minesweeper until the mid-1960’s.

Klipfish sheltering behind a Cape urchin

Spot the fish face... — Spot the fish face…

Cuttlefish cycling through his colour palette

There's a cuttlefish hiding here... — There’s a cuttlefish hiding here…

One of the many speckled klipfish on the wreck

One of the cuttlefish we found next to the wreck

Located a very short distance (less than 1 kilometre) from the slipway at Miller’s Point, the SAS Pietermaritzburg is in quite an exposed position in the bay and as a result looks as bad or worse than the Smitswinkel Bay wrecks. The vessel is resting on its keel with a very pronounced tilt to one side (it was originally sitting upright, but storm damage has caused large portions of the vessel to collapse). The decks have mostly buckled and tilted, making for some vertiginous angles and possible head-bumping scenarios for the unwary photographer (i.e. me). The wreck used to be suitable for penetration, but it’s far too unstable and fallen in on itself now.

The hawse-holes are clearly visible, as well as several hatches. Tony found a toilet, and I located three very respectable looking kitchen sinks. Some kind of pressure vessel (looks like a boiler, but I don’t think it is and for once Tony isn’t sure either!) pushed up through the deck when the decking subsided. There’s also a very large anchor winch on the foredeck which is a cool shape – I kept coming back to look at it.

Last time I dived this wreck I was knee deep in gas-flame nudibranchs; this time I saw only one, but spotted a large number of shy little klipfish, curled up unobtrusively among the encrustations on the wreck (lots and lots of urchins and sea cucumbers). Tony found three cuttlefish, all napping together – what beautiful creatures! There are some interesting bits of the wreck that have fallen off onto the sand on the port side, and I found these to be more colourful than much of the rest of the vessel.

Beautiful resting cuttlefish next to the wreck

Visibility on this site is rarely much to write home about because of its exposed position, and we were extremely fortunate to have about 10 metres horizontal visiblity when we dived it – even after a week of southeasterly breezes.

Looking across the top of the SAS Pietermaritzburg's deck

Dive date: 9 July 2011

Air temperature: 21 degrees

Water temperature: 14 degrees

Maximum depth: 21.2 metres

Visibility: 10 metres

Dive duration: 43 minutes

Walking anemone engaged in eating its favourite food (multicoloured sea fan)

Invertebrates of Malta

We found the marine life of Malta strikingly different to what we are used to at home. I like to think that we are pretty good at finding things, because diving in Cape Town sometimes requires a beady eye, patience, and willingness to stare at what seems like barren sand. To both me and Tony the marine life of Malta seemed far less prolific than we are accustomed to in South Africa, and certainly there are not many invertebrates – in terms of both number of species and biomass – at all. The warm, clean water, which is devoid of plankton, probably does not support the dense aggregations of life that we are used to in the Cape.

Here is a summary of pretty much all the different invertebrates we did see. (You should note that I didn’t have twenty pictures of each creature to choose from… In the ten dives, I saw one hermit crab, one sea squirt, and ONE sea cucumber. Not one sea anemone – though apparently they are there somewhere. Imagine that!)

Nudibranchs

A nudibranch (Flabellina affinis) that we saw often on the deeper wrecks

Worms

We saw lots of fireworms, which have erectile bristles that will break off in your skin if you touch them, and cause irritation because they contain a toxic substance. They move just like centipedes, and occasionally form feeding aggregations – I didn’t get a photo of one, but Tony has some on video.

We also saw a lot of tube worms, some even inside the cave and tunnels we swam through. On the deeper wrecks and less disturbed sites we found very large specimens.

Tubeworms (Serpula vermicularis) inside a cave under Gozo's Blue Hole

The tube worm Serpula vermicularis retracting into its tube

Crabs

Spinous spider crab (Maja squinado) hiding from the camera

Hermit crab (Dardanus arrosor) on the wreck of the P29 patrol boat

Urchins

We saw a few different kinds of sea urchin, but I don’t have scientific names for them…

Sea urchins are light sensitive, so use shells and bits of seaweed as hats

A sea cucumber inside the cave leading to the inland sea at L'Ahrax Point

Sea stars

We can’t move an inch in Cape waters without landing on a sea star, whereas in Malta I think I saw five starfish (individual specimens, not kinds) in ten dives. I was thus disproportionately excited when I did find them!

Irregular starfish (Coscinasteria tenuispina)

This next one is interesting – we find huge numbers of spiny sea stars at home, and I seem to recall reading that they are in fact a European “import”.

Spiny sea star (Marthasterias glacialis)

Ascidians

I say “ascidians”, but this is the only one I saw.

Dive sites: Tivoli Pinnacles

This is a recently discovered site near Roman Rock, named Tivoli Pinnacles because of its position east of Roman Rock (as Tivoli is east of Rome). It’s a very short boat ride straight out to sea from Long Beach, and the site is very close to the approach lanes for Simon’s Town Harbour.

We started our dive on top of one of the southern pinnacles, and drifted with the current, spending most of the dive at about 18-20 metres. The relief is quite flat away from the pinnacles, but there is a lot to see.

A smooth horsefish, trying not to be noticed

Tony found a horsefish, resting in a gap in the rocks, Andrew found an evil eye puffer fish for me to photograph, and I spotted a wide array of nudibranchs – mostly silvertip, crowned and gas flame.

This was a very easy dive in the conditions we did it in. There are ample opportunities to stop and examine the reef as you pass over it, and the depth is relatively constant. It was my second dive of the day and I actually went properly into deco… During the six minute deco/safety stop that my dive computer demanded a large and friendly seal frolicked around us. When we surfaced, he was leaping about next to the boat.

Papery burnupena and other encrustations on a sea fan (possibly!)

Cauliflower soft coral and mauve sea cucumbers

Grant had received a call that there was a large pod of dolphins off Kalk Bay harbour, probably feeding, so we followed the massive flock of cormorants north, and drove past the pod. There were maybe 500 long beaked common dolphins all together, including a lot of very tiny calves. It was beautiful.

Dive date: 5 June 2011

Air temperature: 23 degrees

Water temperature: 15 degrees

Maximum depth: 21.9 metres

Visibility: 10 metres

Dive duration: 42 minutes

Common long beaked dolphins on the surface

Dive sites: SS Clan Stuart

If you’ve ever driven to Simon’s Town along the False Bay coastal road, you’ll have passed the wreck of the SS Clan Stuart on your left. The engine block sticks out of the water at low tide, and only the highest spring tides come close to covering it. The steamer ran aground during a summer gale in late 1914 after dragging her anchor. She was carrying a cargo of coal, all of which was salvaged I think.

Tony getting the gear ready before the dive

The site is quite exposed, and will never boast 20 metre visibility, but on a good day with a calm sea, low swell and the correct prevailing wind direction you can be very lucky (as we were)! The entry is quite hard work. The one we usually use is to park on the roadside outside the old oil refinery and naval graveyard, and kit up there. Walk across the road, climb the low brick wall and find a route down the dunes to the railway line. Take care as the railway line is now in use. Cross the tracks and use the large cement walkway/staircase to get down to the beach. The last step is high – I found it easier to go left over the big boulders on the way down, but on the way up this is too difficult.

Tony films fish under the boiler (his light on the right)

Once on the beach, you can walk to opposite the engine block. The wreck runs nearly parallel with the shore about 40 metres in each direction from the engine block, so you’ll actually hit it almost certainly, wherever you get in. Watch out for the wave on the beach – sometimes it looks small, but with scuba kit on your back you’re heavy and unstable and in a big swell you can get nicely tumbled. Make sure your BCD is inflated before you brave the breakers – you might even want to go so far as to put your regulator in your mouth before you set out. As soon as you are through the waves, put your fins on and swim out into deeper water away from the surf zone. Don’t mess around here – it can spoil (or prematurely terminate) your dive!

The Clan Stuart was made of iron, and although she’s very broken up, much of her remains. The remains of boilers can be seen next to the engine block, and the ribs of the ship are clearly visible as you swim along her length. There are ragged bits of metal decking, and some bollards are clearly visible on the edges of the wreckage.

Blacktail seabream schooling above the wreck

There is a lot to see here – beautiful invertebrate life – abalone, mussels, sea cucumbers, nudibranchs, worms – schools of fish (we saw blacktail seabream), shysharks, and of course the pleasure of swimming the length of a shipwreck! There are also ridges of sandstone to explore, and kelp covers parts of the wreck. Particularly around the engine block, the growth is very dense.

This is a good site for night dives, and seals are often spotted here which is very entertaining. The entry and exit can be a bit of hard work, but it’s well worth it and the depth (maximim 9 metres at high tide) makes it very suitable for training dives.

Kate with the buoy line in top to bottom visibility

Dive date: 22 May 2011

Air temperature: 20 degrees

Water temperature: 14 degrees

Maximum depth: 7.6 metres

Visibility: 10 metres

Dive duration: 48 minutes

Dive sites: Wonder Reef

I think Wonder Reef (or Wonderful Reef) used to be considered separate from the Castor Rock reef. Survey work by the indefatigable Peter Southwood has revealed that it is in fact connected to Castor Rock by a thin neck of rocks. If you look at this map of the area, Wonder Reef is to the south of the Castor Rock area, in the top left hand corner of the map.

Blue gas flame nudibranch with feather stars

Blue gas flame nudibranch with cerata visible

We dived this site with Kate and Andrew, who was doing a photography dive for his Advanced course. The water was very green – the colour of an Appletiser bottle and in some of the pictures I took it looks distinctly like a night dive – but I had fun getting some close-up pictures of the very lush and colourful reef life.

The rocks are covered with anemones, feather stars, sea cucumbers, and nudibranchs. I also found an huge octopus – I don’t often spot them anywhere other than Long Beach!

Kate was my buddy, and I kept thinking I’d lost her when in fact she was swimming just above me, looking over my shoulder at the things illuminated by my flash. On the way up, Tony and I were visited by a sea jelly. This picture shows you how dirty the surface layer is – it was taken at the safety stop.

Dive date: 2 May 2011

Air temperature: 21 degrees

Water temperature: 13 degrees

Maximum depth: 16.8 metres

Visibility: 5 metres

Dive duration: 38 minutes

Exploring: Ark Rock Boiler Wreck #3

We did two short exploration dives around Ark Rock on 21 March. The first was to a small wreck roughly east of the rock itself, and the second one was to check out a pair of boilers lying on the sand s short distance apart. There’s nothing else around except for some rocky reef, which Tony and I explored for a while after we were done with the boiler.

The boiler looks quite imposing – for the technicalities on fire boxes and things visit the Wikivoyage page for Ark Rock, but it’s solitary and impressive. There are no other bits of wreckage lying around. Most of the boiler is very overgrown, and we found a huge roman hiding in one of the holes in the boiler.

Front of the boiler with holes at the bottom

The rocky reef close to the boiler is covered with sea cucumbers, Stephens codium, brittle stars and feather stars.

Tony and I were fascinated with the sea pens sticking out of the sand, and I spent quite a while watching a warty pleurobranch trying to walk over a brittle star (who fought back).

Warty pleurobranch walking over a brittle star

We took a slow swim around the reef and back to the boiler and the shot line, which was on the sand nearby. The water was very green, but the visibility was fairly respectable!

Dive date: 21 March 2011

Air temperature: 25 degrees

Water temperature: degrees

Maximum depth: 16.4 metres

Visibility: 6 metres

Dive duration: 21 minutes

Om nom nom

I spend a surprising number of meal times feeling grateful that I am not a shark or feral cat or other wild animal, and that in general I can be reasonably sure of at least one or two good meals, if not three. Uncertainty about meals must be incredibly difficult – I suppose sharks are accustomed to it? – and as a result most creatures eat as much as they can whenever food is available.

Sea anemone eating a sand shrimp carapace

We don’t often see creatures eating while we dive. It seems to be something that takes place very quickly, with a fair amount of competitive behaviour! Here are some of my favourite mealtime photos from recent dives. Above is a sight we see fairly frequently at Long Beach. There isn’t a creature inside that carapace – it’s long deserted – but the anemone is having a good munch.

Spiny starfish are quite voracious feeders, fairly unusual among our local starfish in that they will eat mussels and other meaty treats as opposed to a pure vegetarian diet. This one appears to be feeding on a sand sea slug. The characteristic hunched body shape indicates that he is feeding. When eating mussels, spiny sea stars will extrude their stomachs into the mussel shell and digest the meal outside their bodies.

Here are some juvenile maasbanker who joined us for a couple of dives at Long Beach in March. They’re nibbling on our bubbles, and on other food in the water column.

We found this little tableau while exploring one of the boiler wrecks near Ark Rock. The brittle star is covered with small yellow, white and black ornate amphipods (Cyproidea ornata) – they look like bumble bees – and it’s possible that the warty pleurobranch is targeting them as its next meal. He’s walking between two radial sea pens.

Brittle star is not having as much fun as the warty pleurobranch

Tony took this video of a little feeding frenzy near the barge wreck at Long Beach one morning. The klipfish are rapidly supplanted by dark and puffadder shysharks, who look very much like their larger relatives as they gulp down the dead fish. Watch out for the school of juvenile maasbanker, too.

[youtube=http://www.youtube.com/watch?v=4e3Je1oro3I&w=540]

To conclude, here’s a sea cucumber. Surprisingly, he is neither full of food, nor feeding (appearances can mislead!). According to George Branch, via the good people at SURG (check out their Q&A section – as you can see on the 2011 Q&A page, I’ve been menacing them this year) this cucumber has been disturbed by something. He’s contracted his longitudinal muscles, giving rise to the shortened, fat shape. With time he’ll relax again to his normal shape.

You can also check out the hungry rock lobster, and the non-sweet eating octopus, for previous food-related posts!

Exploring: Ark Rock Eastern Wreck

Ark Rock is a roughly rectangular flat topped rock (surprise!) off Seaforth beach. On the navy charts it’s marked as Noah’s Ark – its distinctive shape gave rise to the name – and divers typically refer to it as Ark Rock. There is an assortment of small wrecks and other interesting underwater features surrounding it.

Tony and I were fortunate enough to join a small group of divers who planned to explore two undived features that had been spotted on the sidescan sonar attached to the dive boat. Two short dives were planned, so that we could explore more than one site in the area. It was the first weekend since summer started departing that allowed for good False Bay diving – until then, we’d been flailing around in pea soup.

The first site we were to visit is about 85 metres from Ark Rock, roughly to the east – hence the name “Eastern Wreck”. It’s a smallish iron or steel vessel that has been down there for some time. Its actual identity is not known. As we descended through a murky surface layer, we could see almost the entire ship before us.

It’s probably about 15 metres long, only a hull, with some gaps and holes large enough to admit a diver. Even though there were only six of us in the group, it felt pretty crowded on the wreck at times because it’s so small. It might be a fishing boat or similar vessel.

Tony swimming through a hole in the stern of the vessel

The wreck is lying on the sand and is heavily grown over with lovely sea life. There’s no interior structure and no deck or other bits and pieces lying around. I found it really pretty and of an appealingly manageable size to explore in one dive. We only spent 20 minutes on the wreck, which was long enough to survey the structure, but I could have stayed longer and checked out more of the life encrusting the metal remains!

All that remains of the interior structure of the wreck

My photos from this dive aren’t great. I was a bit enamoured of the shape of the wreck – so easily identifiable as a ship – and the good (comparatively!) visibility, so I took too few macro shots and too many green water pictures of indistinct shapes!