Come and join us in the Mother City, a place of reknowned natural beauty where the wonders of the scenery are only surpassed by the underwater magic.
I will tell you a not very well kept secret. We live in Zululand. We revel in the subtropical weather, the sweltering heat of summer and the glorious and crisp sunshine of winter. We develop deep depression if it rains for 2 days in a row. In short we have become climate sissys of note. When it comes to diving we are blessed with the beautiful blue warm water of the southern Indian Ocean brought down by the warm Agulhas current, which reaches a very comfortable 28C in summer and rarely drops below 20C in winter. Much of the year wetsuits are optional.
You would think then that we should rarely venture outside this paradise. This would be true except for one thing. There are places to dive elsewhere in South Africa where the landscape is so unique and the wildlife so exciting that we have no choice but to step outside our comfort zone and explore. Once experienced there is no going back. Wonders to dream about, adrenalin pumping, unforgettable, addictive……and COLD!
This blog is an introduction to some of the cold water wonders of the South African Cape Coast. Come and dive the Cape with us.
In the Cape waters, the warm Agulhas current meets the cold Benguela drift bringing icy water from the south up the Western Cape coast. The two mighty oceans, The Atlantic and Indian meet and mingle off Cape Agulhas, causing powerful currents and eddies. The warmer Agulhas waters flow into False Bay giving the water temperature on this side of Cape Town several degrees temperature advantage, ranging from 14C to 22 C. On the other side of the peninsula the sun warmed surface water is blown away from the coast by the prevailing winds, and is replaced by the icy deep water upwellings of the Benguela current. Here temperatures of 6-14C are more common.
The temperature contrast causes significant variations in fauna and flora, nurturing giant kelp forests, abundant filter feeders and all the hunters of the deep.
But beware, pack your thickest wetsuit!
The deep blue dive is a long ride out from Simonstown and very weather dependent. 50 km off shore there is a natural interface between the warm and cold currents and animals and fish come to feed at this marine rich spot. This is a popular fishing ground and the trawlers are numerous, active, and successful in this area. Fleets of tuna boats may be encountered. The temperature interface may move between 15 and 50 kilometres off Cape Point depending on currents. The day we dived we were 55 kilometres off the Point, a 3 hour boat ride.
The waters out in the deep blue are clean and relatively warm and we were lucky to find temperatures between 21 and 22C which is in stark contrast with the coastal water temperatures.
The trawler activity attracts a large number of predators and opportunists, including sharks, birds, seals and game fish like tuna and other pelagic fish feeding off the bycatch. Because of this there is an opportunity to find some of the migratory midwater sharks. Diving is baited with fresh tuna and brings in the Blue Shark and Short-finned Mako sharks, rarely seen in other circumstances.
Blue sharks (Prionace glauca), are light-bodied with long pectoral fins. The top of the body is deep metalic blue, lighter on the sides, and the underside is white. The male blue shark commonly grows up to 3 metres, the larger females may reach 3.3 m, rarely up to 4 m. The silhouette is elongated and slender in build, elegant and sinuous in movement. They inhabit all the oceans of the world except Antarctica and they migrate long distances, a true greyhound of the sea.
They are viviparous with a yolk-sac, delivering 25 to 50 pups per litter. The gestation period is between 9 and 12 months. Females mature at 5 to 6 years of age and males at 4 to 5. Courtship involves biting by the male and mature sharks can be accurately sexed according to the presence or absence of bite scarring. Female blue sharks have adapted to this enthusiastic and rigorous mating ritual by developing skin 3 times thicker than the male.
In our quest to see these elusive creatures we took a trip with Apex Shark Expeditions out of Simonstown with renowned shark guru and photographer Chris Fallows and his wife Monique. He is an inspirational shark photographer and has the best collection of the breaching Great White Shark that I think exist. He is certainly a committed citizen scientist and has contributed enormously to the shark knowledge of the Cape coast. He runs shark orientated tours out of Cape Town including, at the seal pupping, the trips to see the breaching GWS. Still on our bucket list.
We drove out the 55 km to the site towing a fishing line. These sharks eat live fish and do not respond well to dead bait. To get them close to the boat the skipper will tow a stunned tuna behind the boat on a line.
The sky was blue and the sea deep and clear with a gentle wave. There was chaos around the fishing boats with dolphins and seals diving and surfing and gannets and gulls flying and calling. Albatros and Storm Petrols rafted near by.
We towed our tuna for over an hour until Chris finally spotted the slender blue silhouette under the water and gave us the signal to get ready. The dive plan is more of a surface snorkel with the diver floating off from the boat on a line with snorkel and camera. Tanks are available, and we used them on a subsequent trip, but the sharks are generally drawn to the surface by the bait and the shallow depths are perfect to showcase his beautiful colour. The sharks circle the boat and the bait. Blue sharks rarely bite humans and from the 16th century (I know really!) only 13 bites have been recorded so we felt quite safe.
We saw 3 beautiful blue sharks, large intelligent eyes, slender darting movements and the most beautiful shimmering blue colour. They must be the prettiest sharks of all. These were quite small specimens, maybe 2.5 m. We swam and motored and swam again and searched high and low for his alta ego the Short-finned Mako but we were not lucky that day and he remained elusive. We had a very brief glimpse on a subsequent trip but not good enough to capture. The Mako is the fastest shark but thickset and dumpy and looks rather like a small GWS. He is also aggressive like the GWS.According to our skipper the shark numbers on his trips have been steadily dwindling and the sightings more uncertain. The conflict with the fishing trawlers and the issue of by-catch is a real threat. To give you an idea, it is estimated that 10-20 million Blue sharks are killed each year as a result of fishing.
As the afternoon shadows grew longer Chris felt the weather change and advised we head for shore and we slowly motored back the 3 hour journey as the clouds built up. The waves whipped up and the little boat bobbed. Its best you have good sea legs for this trip, or else a cache of seasick pills. A keen awareness of the vagaries of the weather in this part of the world is a must if you want to avoid joining the many shipwrecks off the Cape. One of the frustrations in trying to organise our trip was the frequency of cancellations due to weather. It may look calm on shore but if there is a front coming they will often not launch. Still it is an incredible and unique experience to see a rare and beautiful animal. Well worth all the effort.
The African or Cape fur seals (Arctocephalus pusillus), live around the Southwestern coast of Africa. With their tiny ears and big soft eyes they are known as the dogs of the sea. Their inquisitive and playful behaviour is reminiscent of naughty puppies and they often come up to interact and play with divers.
They gather into and live in large colonies. While fur seals spend most of the year at sea, they never fully evacuate the rookeries and mothers and pups return to them throughout the year. There are many rookeries around the cape coast, where they can be found all year round, but they become particularly crowded and active during the mating and pupping seasons.
Cape fur seals begin to breed in the middle of October when males haul out on shore to establish territories through display, sparring and sometimes actual combat. The females give birth at the beginning of the summer and mating takes place 6-10 days later and so the rookery in this period is a maelstrom of bleating pups, posturing, fighting males and exhausted females trying to catch a quick kip!
The outcome of this is that there are Cape fur seals to be found when diving and swimming off the Cape coast all year round and it is common for them to dart past through the kelp. It can lead to a heart stopping moment when this fast dark shape glides by as we are ever aware of the ultimate predator in these waters, the Great White Shark.
The seals are inquisitive, quick and playful underwater, especially the juveniles and babies, and so they will come up to the diver and check you out. They love their reflections in the dome ports and are experts at photo bombing a picture by blowing bubbles at the camera through their noses. They nip at fins and trailing equipment and they will sometimes challenge with bared teeth but you can see they are enjoying themselves. The smile says it all!
You don't have to dive to enjoy this unique experience. One of the best seal experiences around is run by Animal Ocean from Hout Bay harbour and yes that is the 6C side! There is a small seal colony on Duiker Island just outside the harbour mouth and in summer they take several boat trips a day with snorkelers to a sheltered cove there, 6-10m deep, to frolic with the seals, weather permitting. We spent a glorious couple of hours, insulated by their excellent quality wetsuits, cavorting with and photographing the seals.
Cow sharks, or to give them their proper name, Broad nosed seven gill sharks, are considered to be the most primitive of sharks. All sharks started out with 7 gills, but evolutionary change saw most sharks drop 1 or 2 sets of gills. Cow sharks have survived 5 mass extinctions and are closely related to fossil sharks of the Jurassic period. They are truly living dinosaurs.
They are considered potentially dangerous to humans because of their aggressive behaviour when threatened, and because human remains have been found in their stomachs, but it is debatable if this is through attack or, more likely, scavenging. There are only 5 recorded attacks on humans in 4 centuries and as recreational divers we did not feel threatened at any time in their company. Maybe a night dive would be different!
They are a slightly odd looking shark. The nose is blunt and the dorsal fin is placed far back giving a snake like appearance when swimming.
Cow sharks live up to 50 years, and they only reach sexual maturity at 20 which is always a vulnerable trait for survival. The conservation data suggests they are endangered but data is sparse.
It is breath stopping to lie in the kelp forests as these creatures lazily drift past.
Although they can be found fairly consistently, they have disappeared for periods of time, sometimes for a few months. The theory of a recent absence was related to an increase in Orca attacks. Carcasses were found minus their livers, an Orca technique apparently. Presumably the survivors moved off to deeper water for a while. They did come back but like with all natures events, nothing is guaranteed. The same thing happened in Gansbaai with the GWS and they left Gansbaai for 3 or 4 months causing major stress to the shark cage diving industry. You would think the GWS bows to no one but apparently when threatened he runs away. Who knew!
Shysharks are common in Cape waters and are often found in the kelp beds. They are bottom dwellers feeding on fish and small crustaceans. They are a small shark, rarely exceeding 60 cm and no threat to humans.
There are four species of shyshark, 3 are only found off South Africa. They are similar in appearance and distinguished by different patinations. This is the puffadder shyshark (Haploblepharus edwardsii) which is more slender than other shysharks, with a short, broad, dorsally flattened head and a narrowly rounded snout. It is strikingly patterned with a series of dark-edged, bright orange "saddles" and numerous small white spots over its back. I think this is the prettiest of the shysharks
When threatened, the shy shark curls into a circle with its tail covering its eyes giving rise to the names "shyshark" and "doughnut". It will curl around your forearm. It seems to me this is not the best anti predator strategy, and they are slow and very easy to catch, but apparently the round shape makes it more difficult to swallow. It must depend how big the mouth doing the swallowing is I guess !
Shysharks are oviparous and females deposit egg capsules singly or in pairs onto underwater structures, so called mermaids purses.
Sea hares are a type of gastropod mollusc with a soft internal shell. They have earned the name sea hare because if the round shape and the long rhinophores which look like bunny ears, as well as their fondness for sea weed and sea lettuce. They are closely related to Nudibranchs and something we have not really had much opportunity to see before. They are however quite widely distributed in the world, usually in tidal, coastal and sandy bottomed areas
The Shaggy Seahare (Bursatella leachi africana) is well recognised in the Cape but said to be a rare sighting. We went for a shore dive looking for them off Simon’s Town. The dive shop sent us off on our own you see, with instructions to collect a homeless guy from a shelter to act as car guard!. We were determined and we scoured the area searching for over an hour. It was cold so you can see we were very focused! Well just as we were about to give up, we had an ahah moment. The sandy bottom was littered by pinky white shaggy blobs which were, infact, the Shaggy Seahare. Eureka
We had been swimming over them the whole time. Once we saw them they were clearly present in profusion. They even formed chains of mating animals across the sea bed. This is a well documented behaviour. They are hermaphrodite and in the chain the one at the front acts as a female and the one at the back as a male, with the animals in-between having dual sexual roles. Like a slightly pornographic conga line!
This type of mass gathering is triggered by a pheromone from the egg packages and causes the hares to aggregate and mate. Each species releases a slightly different pheromone and they have been called collectively Attractins. Attractins are the first waterborne peptide pheromones to have been isolated and characterised in invertebrates. Well fancy that.
The books say that they can disappear as suddenly as they arrive so these pop up raves are apparently quite variable. We were lucky.
Nudibranchs are a photographic delight and we have a profusion of species in our local dive sites. Cape Town however has an even richer abundance and variety of nudibranchs many of which are described as unique to these waters. For example the species shown above is the Medallion Silvertip Nudibranch. Some of the species can only be distinguished from one another by their eggs. This species differs from the Gas Flame Nudibranch (a common East Coast nudi) The difference lies in the fact that the cerata (pointy things on the back) are broader and have digestive tracks in them in the Silvertips.
The Silvertip belongs to the Janolus family which are characterised by an organ between the rhinophores on its head, called the Janolus organ. It looks like a little nob or cockscomb. The function of this organ is as yet unknown.
Nudibranchs are functionally blind. Having only rudimentary light receptors they hunt using tactile stimuli but the most important is chemical scenting. The Janolus sp feed on different Bryozoans.
The Great White Shark (GWS) carries an almost mystical aura as the apex predator of the seas, an aura advertised and driven by the Jaws hysteria. GWS live off almost all coastal and offshore waters with temperatures between 12-24C. One of the densest populations is found around Dyer Island off Gansbaai in the South African Cape. For this reason it has become a popular destination for cage diving with GWS.
The GWS is epipelagic, although gathering in coastal areas rich in prey, they also travel long distances in the open water. South African GWS have been tracked to Australia and back, a journey of 20,000 km in under 9 months, possibly for seasonal mating and feeding.
They are impressive physically as well as for their feats of circumnavigation, and can grow to measure up to 6 m in length and over 1000kg. They have a bite force of over 18,000 Newtons, in short they are indeed well engineered killing machines. In South Africa they prey on the Cape Fur Seal and are particularly active during the seal pupping season. They usually strike from below at high speed resulting in an impressive breach attack which is unique to the South African population. They are the most feared of sharks and have been responsible for over 300 documented unprovoked attacks.
The conservation status is uncertain but likely to be vulnerable. Data is deficient.
It is for this fearsome reputation that most underwater contact is organised through cage diving. There is some controversy regarding this practice as it has been said that the sharks begin to associate human activity with food, a potentially hazardous situation. Responsible operators chum the waters but do not feed the sharks, the chum attracts curious scavengers who soon swim off when the scent trail does not lead to a meal.
We dived on 2 occasions with different operators, both of which were professional and committed to sustainable tourism.We had good opportunity to see the sharks above and below the water although underwater visibility was not good. I think that is par for the course. It is a heart stopping experience to see these massive creatures cruise up to the cage, their black obsidian eyes looking straight through you. You know you are in the presence of the ultimate predator.
At the end of the day we were happy we did it but it is rather reminiscent of visiting a zoo to see animals instead of going on safari. There is no real comparison. Would we go again? Probably not. We will wait for an encounter in the open sea. After all they occasionally put in an appearance in Sodwana and on the Sardine Run.
The experiences we have shared with you took place over quite few visits to Cape Town and, before a Cape diver takes umbrage, it is far from a comprehensive overview of the diving offered in this diverse and challenging environment. More of a taster.
There are numerous dive sites all around the peninsula, shore dives and boat based diving, and there are many many shipwrecks to add colour and adventure to the already beautiful landscape.
The Cape diver is something of a fanatic, proud of his physical resilience, fiercely protective of his local fauna and flora, enthusiastic photographers and citizen scientists. They often look like tech divers with drysuits and hoses sprouting. Sometimes they may come across as a tiny bit superior but it is probably the effects of the cold! I feel very forgiving as I bob around in my 28C backyard.
We will be back, that is for sure, and there are many treasures yet to find. It is just we have to gird our loins against the icy chill of that water.