Diving at the Two Oceans Aquarium

For Tony’s birthday in June we spent a Sunday morning at the Two Oceans Aquarium at the Waterfront, diving in the I&J Predator Exhibit and in the Kelp Forest Exhibit. These were two of the best dives I’ve ever done. You need an Open Water or equivalent qualification for the predator tank, though I think you can do a (expensive?) DSD there too. For the kelp forest you need an Advanced qualification, as even though it’s only 6 metres deep, it’s very surgy.

On both these dives, you are on view to the public. It’s fun to wave at the kids through the windows of the displays. They are very excited to see real live SCUBA DIVERS in the water with all the fish. Needless to say, the scuba divers were very excited to be there!

Youtube videos for both dives can be found here.

Kelp Forest Exhibit

We started in the kelp forest – you wind your way up to the roof of the aquarium and drop into the water off a small wooden platform. This exhibit completely is open to the air, since it’s comprised of vegetation and sea creatures found in Cape waters, and because kelp loves sunlight. Kelp also likes water movement, so there are a variety of devices to keep the water moving – dump buckets, a plunger, and some pumps. This makes it quite choppy on the surface and quite surgy below. (Fascinating fact: since kelp cleans the waste products – such as ammonia – out of the seawater by filtering it, a lot of the aquarium’s water is passed through the kelp tank on its way to other exhibits.)

The exhibit has live kelp that is actually growing, which is quite an achievement, but you’re not supposed to hang onto it the way I sometimes do in the open ocean! The tank is packed to the brim with white steenbras (my absolute favourite), red stumpnose, galjoen, zebra, roman, shysharks, fransmadam, and even a gully shark if you can spot him. The fish are huge, many of them much larger than any I’ve seen in the ocean. I was extremely fortunate to be allowed to feed them – I was given a small bag of squid pieces and sardines, and the fish gathered around me as I knelt on the bottom. It was wonderful, so busy and colourful. They weren’t shy, bumping into my legs and BCD once they’d realised I had lunch with me. There’s a hilarious finger-biting episode at around 2:45 minutes in this video:

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

The water is cold, and the tank isn’t actually very big. There are nice swim throughs between the rocks (made of fibreglass) and the kelp. The visibility isn’t perfect as the water is so highly aerated, and there are little bubbles of air everywhere. But it’s a thrilling dive and a very rare opportunity to get so close to so many beautiful fish.

Dive date: 6 June 2010

Air temperature: 18 degrees

Water temperature: 14 degrees

Maximum depth: 5.7 metres

Visibility: 10 metres

Dive duration: 27 minutes

I&J Predator Exhibit

The second dive we did was in the predator tank, which is a lot warmer than the kelp forest. On this dive, the Divemaster was armed with a piece of broomstick to “guide” the sharks away if they were to bother us. There are five ragged toothed sharks in the exhibit, none more than two and a half metres long. I think they’re all female. They cruise round and round in circles, looking completely awesome. I spent a long time just sitting on the floor of the tank watching them.

The other magnificent inhabitants of this tank are the sting rays. There’s Olive, a giant (and I mean GIANT) short-tailed sting ray like we see at Long Beach and Miller’s Point in summer, and a whole host of small (the sort of size that makes you want to take them home as pets) devil rays. Tony spent a significant part of the dive (while I was sitting watching sharks) chasing tiny rays around with his camera set on video.

In the corner of the tank we met the loggerhead turtle. She was lying next to a water vent, with her head in the corner. I was allowed to touch her on her neck (it felt really soft, and I felt lucky). I wasn’t convinced that she was a happy girl – she looked kind of depressed. Our DM said she gets more active when the water temperature increases, and sure enough I saw her swimming happily past the glass in the predator tank two weeks ago, when I went for my Saturday morning training at the aquarium.

The tank also contains musselcrackers, garrick, yellowtail, and (at the moment, but not when we dived in it) the remains of a sardine baitball.

The only moment when I got a bit of a fright was when we were surfacing against the rocks in the middle of the tank, and I omitted to look where I was going: straight into the path of a raggie. And sharks don’t generally get out of the way! Fortunately our DM had seen me behaving like a space cadet and “guided” the shark off to the side (since I wasn’t able to interrupt my ascent quickly enough).

Dive date: 6 June 2010

Air temperature: 16 degrees

Water temperature: 18 degrees

Maximum depth: 5 metres

Visibility: 25  metres

Dive duration: 35 minutes

Exploring: North Battery Pipeline

Tony has been eyeing the pipeline just south of the Lower North Battery (that collection of navy buildings with gun turrets on the Main Road just before you get into Simon’s Town) for some time. It’s north of Long Beach and further north than the wreck of the Brunswick. Even though I was coming down with what turned out to be a vicious bout of flu, I was determined to get in the water (I reckoned I was getting sick anyway…) so we went exploring one Sunday morning in midwinter.

We parked the cars on the southern side of the North Battery – there’s a little driveway and we pulled them out of the way onto the grass (here it is on Google Maps). There’s also space for just one car, pulled right off the road, right above the entry point. From there it’s a bit of a walk along the pavement, down a slope, over the railway line and then down to where the pipeline starts. You can see the single-car space next to the piece of fence, and below it the start of the pipeline to the left of the rocky outcrop in this image from Google Maps.

The entry isn’t too bad. There’s a barnacle-encrusted concrete promontory that we sat on to put our fins on, and then (theoretically) dropped forwards into the water, which was just over waist deep. While putting on my fins I got washed over backwards onto the wrong side of the promontory (thank you for my thick wetsuit!) but that turned out to be fine, as it was sheltered, and eventually I managed to get clear of the swell and kelp with a little bit of effort.

North Battery Pipeline entry point
North Battery Pipeline entry point

We followed the pipeline straight out to sea. It’s not very long, but quite undisturbed, with lots of abalone and rock lobsters. There are one or two leaks in the pipeline, emitting a brownish liquid whose origins we preferred not to speculate on… it looked warm, or oily, because it shimmered a bit before mixing with the surrounding water. Tony thought it might be mountain water (tannins causing the brown colour). Hope so. Right at the end of the pipeline the visibility got really poor from all the stuff flowing out, so we turned south.

It’s all sand south of the pipeline, with lots of beautiful anemones and countless sluggish puffer fish buried in the sand. We turned after a hundred metres or so, and swam back closer in to shore. There we found what looks like the remains of a ship – four or five big rusty bits of iron sticking out of the sand in relatively shallow water. I don’t think it’s part of the Brunswick – I think we were too far north – but it could be.

Verdict: Glad we checked it out. Lots to see on the pipeline (good for macro photography) but be careful about the poor visibility at places. Curious about the bits of ship (I assume) inshore, south of the pipeline.

Dive date: 18 July 2010

Air temperature: 17 degrees

Water temperature: 12 degrees

Maximum depth: 6.5 metres

Visibility: 5 metres

Dive duration: 30 minutes

Wreck diving

There is just something so intriguing about diving a wreck and this need not be limited to ships alone. This tank wreck in the Red Sea is an amazing dive.

Sunken tank in Jordan
This tank was placed as an artificial reef by order of the King of Jordan, who is a diving fanatic!

Wrecks all have a story to tell. Some are there from navigational errors (like the Kakapo on Long Beach, Noordhoek), some from mechanical faults, some from war battles (like the HNMS Bato off Long Beach, Simon’s Town), many of them as a result of bad weather (like the Clan Stuart)  and some wrecks are the result of a planned scuttling to form an artificial reef (for example, the Smitswinkel Bay wrecks).

No matter how it got there, exploring a wreck is fascinating and within months of its arrival marine life forms move in and make the nooks and crannies home. Corals, sponges, sea anemones – to name a few – all appear and grow within months of the wreck’s arrival. Wrecks can sometimes become home to more species than you see on a nearby reef purely due to the wreck’s size, giving juveniles far more protection from rough weather than a reef can.

Despite the allure of the many opening and overhangs, wreck diving has its own set of hazards and without proper training it is important to stay out of any overhead environments. It is also critical to avoid becoming entangled in the myriad of cables, ropes, chains and often fishing tackle that can sometimes be draped over a wreck. When you start wreck diving you will most likely be content to swim around the outside and be awed by the size of some wrecks, once majestically sailing the seas, brightly painted and full of noise and life. Now they lie silent, rusty and overgrown, but still teeming with life.

A powerful dive light is a must if you want to peer inside holes and hatches, but be wary as your light can often disturb some huge creature who will buzz by you startled and dazed by your light, as you are blocking the exit.

Shark tale follow-up

After his shark sighting at Long Beach last week, Tony emailed local guru Georgina Jones of SURG – more on SURG (Southern Underwater Research Group), and Georgina’s work in particular, will follow in another post (probably a book review). Tony wanted to find out whether his observation that there was no visible marine life, no fish and no movement at Long Beach on the day he saw the shark had anything to do with the presence of the creature, or whether it was uncorrelated. Georgina passed Tony’s email on to Alison Kock at Save Our Seas, a veteran white shark researcher based in Cape Town.

Alison’s reply – which is filled with fascinating nuggets of information about shark monitoring in Cape Town and great whites in general – is reproduced below:

Thank-you very much for forwarding this encounter. I keep a database of all white shark-human encounters in Cape waters and with your permission would like to add this encounter and your name, Tony and contact numbers to this database. Interestingly another sighting in the same area was recorded on the 23 August, and there were two white shark sightings at Fish Hoek on the 25 Aug, and one on the 24 and one on the 20th (sharkspotters.org.za has sightings recorded at shark spotter beaches).

Tony, regards your observation one would certainly expect that larger fish and seals would be absent from an area temporarily where a white shark is patrolling. However, it’s also conceivable that smaller marine animals could perceive the shark as a threat. A huge misconception is that white sharks only eat these larger animals, but various smaller fish and invertebrates (bivalves, cuttlefish, squids, octopus, pilchards etc) have also been recorded in white shark stomach contents, particularly smaller sharks (Geremy Cliff data). Thus, these animals may also respond to an immediate presence of a white shark if perceived as a threat. However, I wouldn’t expect this behaviour to persist for long periods of time.

We have deployed small animal-borne cameras on white sharks over the years and have been able to get a sharks POV of what happens on a reef when the shark swims over it. Some smaller fish which you wouldn’t think to be on the menu do react by swimming out of harms way. However, the behaviour is usually instantaneous with ‘normal’ behaviour by the fish resuming almost as soon as the shark’s head has moved past. When we observe white sharks around the research boat, we record similar behaviour, the chumming often attracts large groups of various species of ‘bait fish’, these fish almost always respond to the approaching shark by moving out the way temporarily.

Thanks Alison!

Shark tale

As a freelance instructor I dive at Long Beach behind Simon’s Town railway station several times a week. Long Beach is an ideal training site as it offers protection from the weather under most conditions, visibility is almost always 5 metres plus and it is one of the easiest shore entry dive sites around the Cape Peninsula.

On Wednesday 25 August I was on a training dive with three students. I briefed them as usual and off we went. The visibility was around 6–8 metres and I was surprised to find nothing to show them. Around the barge, over the fishing boat, down the inner pipeline, nothing to be seen. I was starting to feel the place was barren, and it was very strange. Suddenly a klipfish came racing across the sand faster than I believed they could swim and I half expected a seal to be close behind as I had seen one on the surface before we started the dive, but nothing. I honestly couldn’t find anything, no shysharks, no pipefish, no crabs, no octopus and I can almost guarantee I will find these creatures there on any dive. Not even the hundreds of busy little hermit crabs were scurrying around and I could not find any movement. I started to think that perhaps the water had been poisoned by some ship or something weird and all signs of life had moved off somewhere else.

We were just reaching the western end of the outer pipeline, about 60 metres offshore and at a depth of around 5 metres when I looked up and less than five metres away was a 2-3 metre great white shark. She was just cruising very, very slowly and must have seen us long before we saw her. I was most awestruck by the shark’s graceful poise and her girth. The other impressive feature was the length of the pectoral fins. She circled slowly around us and them slowly swam away, close above two other divers in the water not too far from us, and disappeared.

What to do when you see a shark?

Well, we all have our own theory and during briefings we always tell divers what we will do and how we will react. But will we react the way we think we will, and how will we deal with divers that panic?

I always brief divers as to what I will do and what they should do, and this is what we did. We all dropped to the sand, me first as I saw it first. I pulled my buddy, the most jumpy student, down and deflated his BC well before he saw it, I then pulled the other pair closer and dumped their air. It was a family and the youngster was 13 years old. He saw the shark but did not know what he was looking at. We then swam slowly back to shore without seeing the shark again. The first thing they said was ”I thought you said you never see great whites here!” so I had egg on my face as I had just said that – honestly – as I had never seen a great white there before! Oh well…  I will need to modify my dive briefing slightly now!

In all reality the shark had been watching us for a while, possibly thinking “man, they make a noise.” According to the Introduction to Sharks course offered by SharkLife (it’s free and fantastic – do it now!), sharks are highly sensory creatures. Sharks have eyes on either side of their heads, which means they have a nearly 360 degree visual field (compare that to the approximate 120 degree width of your visual field when wearing a scuba mask). They have a small blind spot directly in front of their snouts – too small for you to hide in! – and another one just behind their heads. They can focus their eyes at a range of distances, and have excellent vision even in low light conditions. Sharks also have excellent hearing, augmented by a “lateral line” which extends along their bodies and provides additional sensory information.  Their sense of smell is likewise highly developed. In a great white shark, 18 percent of its brain mass (largest percentage of all sharks) is devoted to the processing of olfactory (smell) information. As if this arsenal of highly developed sensory organs is not enough, sharks also have electroreceptive cells called Ampullae of Lorenzini located around their snout and head area. These cells can detect tiny bioelectrical impulses given off by muscle movement of potential prey (which is why it’s a bad idea, as a spearfisherman, to swim along with dying fish attached to your belt). The Ampullae are sensitive to temperature, and are also used in navigation.

Anyway… the shark swam a circle wondering what on earth we were looking for, and then swam off looking for something to eat. Clearly she did not find our presence worthy of investigating or for that matter munching. This just shows that divers that are slowly swimming along with good buoyancy, looking at the marine life in the ocean are just not on a sharks’ to do list.

Great white shark in Mozambique
A great white shark I photographed in Mozambique

Divers seldom get to see great whites. I have been diving for 18 years and have only seen three on a dive. I have done over 100 dives at Long Beach in the last year without seeing one and numerous dives at other dive sites in Cape Town, including at Sunny Cove where I was sure I would see one. Without a single sighting. So remember: stay calm, stay together and enjoy the moment because it is not something you get to experience too often.

If you want to chat about this, please email me!

Exploring: Fisherman’s Beach

We’ve driven past Fisherman’s Beach countless times on our way to stalk the baboons at Miller’s Point, and it’s been on the to do list to dive for a while. We’d heard that it was an easy dive akin to Long Beach, and a good training venue. Also, the little wave breaking on the bright white sand makes it look almost tropical – very inviting.

We ended up diving it the same day as we checked out Sunny Cove. It’s very pretty, with low rocky reefs on either side of the beach, and a wide strip of sand across the middle. There’s lots to explore, and it certainly isn’t as busy as Long Beach. It’s a short hop down the coast to A Frame, and the marine life is thus very similar. There’s a little bit of kelp, but it’s not dense and because of the layout of the site one tends to swim around rather than through it.

Tony’s camera misted up a bit in the warm car between dives, so he didn’t take many photos, but the invertebrate life poses very nicely and there is a lot of colour and light owing to the shallowness of the site.

Fisherman’s Beach is quite exposed, far more so than Long Beach, and we’ve seen that the wave on the beach can get angry in a big swell. Also, there’s a lot of fine sand in between the rocks, and I’d imagine this can get stirred up and decrease visibility quite a lot in inclement conditions. Even some of my careless fin kicks enveloped me in a cloud of particles – so this is perhaps a good place to take more advanced students (for dives three and four of an Open Water Course, for example).

There is parking across the road, and space to kit up on the pavement or on the grass above the beach. There is an easy staircase down to the sand, and although there is more wave activity than Long Beach most of the time, it’s not as intimidating as the Clan Stuart can be.

Fisherman's Beach
Fisherman’s Beach – walk down the beach and into the sea

Verdict: Potentially a good training site, well suited for macro photography, and an easy equipment testing location for when Long Beach is too busy or too familiar.

Dive date: 4 July 2010

Air temperature: 24 degrees

Water temperature: 13 degrees

Maximum depth: 8 metres

Visibility: 12 metres

Dive duration: 37 minutes

Exploring: Sunny Cove

Tony has been wanting to dive Sunny Cove practically since he first set foot in Cape Town, having read in an old book on South African dive spots (The Dive Sites of South Africa – Anton Koornhof) that seahorses had been found there in the sea grass. Tony loves seahorses.

I put my foot down, repeatedly, until it was the dead of winter and the Sharkspotters website told me that not a single great white had been seen patrolling the coast for a couple of months. Sunny Cove is at the end of Jagger Walk, the catwalk that runs along the western edge of Fish Hoek Bay. It’s the site of at least one fatal munching by a great white, and I didn’t want to take any chances.

Sunny Cove railway station
View from the bridge over the railway line towards the dive site

It’s a shore entry, and we parked on the road at the bottom of the steps over the railway line. It’s quite a strenuous walk over the bridge with all your kit on. We spent a while figuring out where to get in – you have to clamber over some rocks, and make your way through dense kelp before getting to a clear spot. Once we decided where to get in, we were glad to be wearing thick wetsuits, otherwise we would have been scraped and scratched quite liberally! There is a huge submerged concrete block just where we got in – at first I tried to swim over it, but realised it was in only a few centimetres of water, and made my way around it. (Fortunately there was no one on the shore with a camera!) Cape Town shore diving is hard on your kit.

Sunny Cove
Our entry point is on the far left, almost out of the photo, where the straight piece of rock sticks out.

The actual dive site is aptly named. The sun streams in through the kelp, and the sea floor looks a lot like Shark Alley near Pyramid Rock – lots and lots of urchins, with pink-encrusted rock formations. We saw a little bit of sea grass, and spent a lot of time examining it for signs of life, but didn’t even find a pipe fish, let alone seahorses! There’s a lot of invertebrate life on the rocks – feather stars, brittle stars, abalone – and we saw quite a few fish.

We did see the deep channel that the sharks probably use to get in and out of Fish Hoek Bay. We were hoping to spot the beacon that records movements by tagged sharks past Sunny Cove, but no luck there. We did not explore much to the south of our entry point – that’s on the to do list (along with more sea horse hunting) for another shark-free day.

Verdict: Shallow, easy dive but a fairly tricky entry and exit. Infrequently dived, so rather more lush and unspoiled than busier sites. Videos of our dive are here and here.

[youtube=http://www.youtube.com/watch?v=DaxvdFG4Fdg&w=540]

Dive date: 4 July 2010

Air temperature: 21 degrees

Water temperature: 13 degrees

Maximum depth: 10 metres

Visibility: 6 metres

Dive duration: 32 minutes

FAQ: What about sharks?

You had to ask! I’m glad you did. As divers, we are venturing into the sharks’ domain, and it’s a risk we take. This might sound scary, but it’s important to bear a few things in mind. First, the ocean is a big place. It’s very unlikely that we’ll meet a shark, unless we go looking for them. Second, even though sharks are wild animals, they don’t like to eat people. Great white sharks need a huge amount of energy to keep their incredibly powerful bodies warm and mobile. That’s why they eat seals – conveniently packaged in a very thick layer of calorie-rich, nutritious blubber. Humans just don’t have the same appeal. That’s why many shark attacks are “bite and release”: the shark takes an exploratory nibble, because he thinks you’re a seal, and when he realises you’re not as tasty and fatty as he thought, he lets go and swims away. Unfortunately, with so many sharp teeth, a shark’s exploratory nibble can hurt you quite badly.

You might be thinking that what you’ve just read proves it’s a terrible idea to dive where sharks are found… especially since we often see seals on our dives in Cape Town. What’s to stop a shark from getting confused between a diver in his black wetsuit, and a sleek little seal? The answer to this relates to how great white sharks hunt. Their hunting technique is to launch themselves from the bottom of the ocean, up towards the seal on the surface. This enables them to reach enormous speeds and to take the seal totally by surprise. Often the shark will breach right out of the water with the seal in its mouth.

Why doesn’t this worry us? Because we spend most of our time on the bottom. For one thing, sharks can’t usually get underneath you to attack. There isn’t much chance of the shark mistaking you for a meal – in fact, it’s more likely that if you see a great white, he’ll just cruise right on by without paying you any attention. Another reason is that the places we dive that are frequented by seals (Partridge Point, Duiker Island in Hout Bay, the Clan Stuart, Long Beach for example) simply aren’t deep enough for a shark to mount an attack. They prefer to get their snacks out at Seal Island in the middle of False Bay (where the shark cage diving takes place), where there is a deep channel around the island perfect for hunting.

There has never been a great white shark attack on a diver in the Cape, despite the attacks we have had on swimmers, spear fishermen and surfers. That’s because surfers and swimmers are usually flailing around on the surface, and spear fishermen are usually dragging a handful of dead or dying fish behind them sending out distress signals to all the predators in the vicinity, so you can forgive the shark for getting confused and thinking they were a meal! You can see some general shark attack statistics (for the whole world) here.

If you dive with me, I will give you a shark briefing if I feel it’s necessary. I’d also like to encourage you to join me sometime for a dive at Shark Alley in front of Pyramid Rock in False Bay. This is a shore entry site where sevengill cowsharks can be seen in large numbers, with near certainty. They are beautiful creatures, up to about three metres long, and are not harmful to divers. We swim to the sandy patch among the kelp where they like to hang out, and then sit on the sand and wait for them to visit us. They are curious, and swim very close to take a look, and then swim away. It’s breathtaking – in a good way! You can see some videos of past dives I’ve done with these sharks on my YouTube page. Diving with these magnificent creatures will change your perception of sharks in general, and may also help you to master any shark-related fears you may have.

Sevengill Cowshark near Pyramid Rock
Sevengill cowshark at Shark Alley, near Pyramid Rock. These curious sharks will approach to within a few feet of divers to get a closer look.

For information on shark spottings in Cape Town, visit Sharkspotters (here too). For information on the relative risks of a shark attack compared to other things (lightning strikes, bicycle accidents, etc – the home improvements section is highly recommended!) go here.

As of yesterday (25 August) I can speak from first hand experience – after a just under a year in Cape Town, I was buzzed by my first great white shark. She circled us, and then left. It was awe-inspiring, and left me feeling honoured to have encountered one of these incredible creatures. I mentioned it in my newsletter today.

(This information also appears on my website, here.)

FAQ: Can one scuba dive in winter?

For one thing, divers don’t mind the rain… they’re going to get wet anyway! But, surprisingly, winter diving in Cape Town is often better than summer diving. At least part of this has to do with the fact that conditions are ideal for diving False Bay (my favourite side of the peninsula), where the water is warmer than the Atlantic. The prevailing winds are northwesterly, and this flattens the sea in False Bay. The bay is also protected from the winds to some extent by the mountains around it. The result is that the visibility in winter is magnificent. The water is a bit colder (more towards the 12 degree end of the range), but because the air is cooler than it is in summer, you won’t actually feel much of a difference, and in fact it often feels relatively warm. Cape divers will tell you that winter is the best time for diving here – don’t miss it!

(This information also appears on my website, here.)

FAQ: Isn’t it too cold to dive in Cape Town?

Water temperatures in Cape Town tend to vary between 7-10 degrees celcius on the Atlantic side, and 12-22 degrees in False Bay. This is chilly, I admit, but the rewards for braving the cold are huge. We have an incredible selection of reefs, wrecks and kelp forests to explore here, and an astonishing variety of marine life. The way to deal with the cold is to wear the right gear. Two wetsuits (a shortie on top), thick gloves and booties, and – most essential – a hoodie – will keep you toasty warm and will enable you to enjoy leisurely dives in our rich waters.

(This information also appears on my website, here.)