The Scientists at Work blog on the New York Times website featured an article by a scientific diver who ventures under the ice covering Lake Untersee in the Antarctic to collect samples of microbes that live there. Ice diving is uniquely hazardous, but the divers who venture below the ice are privy to a strange, magnificent world of crystal clear water and miraculous light patterns. Paul Nicklen has some underwater photographs taken at the ends of the earth in his book, Polar Obsession.
Included with the article – which gives a good idea of the nitty gritty of what is involved in this kind of expedition – is this otherworldly video that made me very happy:
Here’s a sobering, long read for the early days of the new year. Tim Zimmermann wrote a detailed piece for Outside magazine in 2005, recounting the remarkable events that took place in October 2004 at a deep freshwater cave called Boesmansgat. A team of crack technical divers executed a mission to raise the body of a young man who had died while diving the cave ten years before. Things did not go according to plan, and I can’t explain to you how remarkable and tragic the outcome of the dive was.
Cecil lent us the DVD, and Tony and I enjoyed this glimpse of an underwater world replete with both beauty and danger. The Yucatan peninsula in Mexico, where the documentary was filmed, is riddled with cenotes (like the blue holes of the Bahamas shown in this documentary) connected to a giant aquifer. Bougaerts and his colleagues seek to map the connections between the cenotes, and spend hours both underwater and on land extending their maps. They use old fashioned mapping techniques underwater, and computer software on land to develop the maps.
The diving technique of the cave divers impressed me. They frog-kick (instead of finning up and down), and the smallest movement seems to propel them forward. All the diving they do seems to be sidemount diving, with an intimidating number of cylinders. Access to the cenotes is often down steep slopes or even vertical walls, requiring a lot of perspiration just to get yourself and your kit to the water.
These divers are determined, and tolerance for errors is nil. There are no flustered, disorganised cave divers (not ones that survive, anyway). I am in awe. It’s beautiful and pristine, but I don’t think it’s for me!
Here is some pretty terrible footage that Clare (she admits it) took while we were diving at Marico Oog. There is so much natural light in the shallower water that her camera got totally confused! But it gives you an idea of what the place looks like.
Marico Oog is a natural spring, the source of the Marico River. It is located on a farm in the North West Province of South Africa, and we visited it on our way home from Botswana in March. It’s possible to dive in the spring, which is mostly why we took a detour off the N4, the boot of our tiny rental car loaded with a couple of rented cylinders and our dive gear.
Heading off for a dive
The water in the Oog is crystal clear, and water lilies grow around the sides in the shallow (1-3 metre deep) water. The bottom is covered by lush green vegetation that looks like salad, and the bottom in the deeper areas is silty and causes great clouds to obscure the visibility when it is disturbed. Entry is via a ladder, and the initial swim is through shallow water filled with lilies, their long stalks curling towards the surface, where lily pads provide landing spots for dragon flies.
Water lilies
A small pool (less than 10 metres wide) that drops down to about five metres’ depth appears on the right; the very bottom here is muddy, but lilies line the edges. A small ridge separates this pool from the main pool, which is perhaps 20 metres across and has three distinct zones of vegetation. The top area surrounding the pool has a flat bottom and is covered with water lily plants. From 3-6 metres there is green foliage, and from 6 metres to the bottom of the pool is mud.
Sign for divers
The rocks underneath which there’s a swim through
Dive platform seen from below
It’s a diver! One of the few photos of me underwater
Approaching the ladder to exit
View to the bottom from the dive platform
A platform is suspended from drums at about 6 metres, and is used for skills training by the Johannesburg dive schools who sometimes bring their students here (not much sea in Gauteng). At the very bottom of the pool, a pipe descends under a rock, from which the spring water is collected for bottling. The rock apparently forms part of a swim through, which I was not about to try. Willie, the owner of the farm, told us that a trained cave diver had reeled out 100 metres of line (resonably taut, I hope) in a dive beneath the rock, so there’s enough space to travel quite far below the Oog towards the very source of the spring.
These fish feed in the silt at the bottom of the Oog
Black bass and fry
Black bass (I think)
Crab
The fauna inhabiting the Oog is not prolific, but we saw several crabs in the mud, and a number of fish. I’ve struggled mightily to identify the fish, some of which seem to feed from the silt at the bottom of the pools, and others of which look like bass or tilapia and were seen with a huge cloud of fry. There are also eels, but we didn’t see any. We did spot a giant monitor lizard clambering about at the edge of the reeds while we were watching birds returning to roost in the reeds and feed at the Oog in the evenings.
Plants growing at the bottom of the shallow part of the Oog
Transition between different types of underwater vegetation
The slope into the deep pool
It was interesting to dive in a freshwater environment – in contrast to the usual 7 kilograms of weight I use to sink me and my 8 millimetre Cape Town wetsuit for a shallow dive, I wore 3 kilograms, and not even on a weight belt. Two kilograms were in my BCD pockets, and the 3rd kilo, added as an afterthought, moved from by sternum to behind my knee during the course of the dive. The migration of a square block of lead through my wetsuit was something of a distraction, it must be said.
Tony took this picture of me swimming out of the deep hole
Water lily pads on the surface
Water lily stems
Water lily pad
Lush water plants in the mid depths
Water lily stems
Marico Oog is a popular night diving destination, and when the moon is full it must be magnificent. It is recommended that not more than eight divers use the Oog at one time, and even this would be quite cramped for my taste. We were fortunate enough to have it all to ourselves, and for my second dive of the day I was all alone. Tony observed the most of my second dive from the pontoon attached to a cable that can be pulled out over the Oog – it was novel to dive in water so clear that we could see each other in the different mediums.
Reeds above the surface, water lily stems below
I’ve been wanting to go to Marico Oog since Tony told me about it when I met him, but thought I’d never get there because it’s so remote. Actually, it fitted in quite well with flying to and from Lanseria airport and driving to Gaborone – we took a lot of dirt roads to get there, but there’s a tarred road running straight past the farm from Zeerust. If you’re in the vicinity and fancy some total relaxation and beautiful diving, a visit to Marico Oog is highly recommended.
Marico Oog is a natural spring located on the Grootfontein farm in the North West Province, belonging to Willie Muller and his family. We took a detour from Zeerust to the farm in order to dive in the spring, and to spend a couple of days without cellphone signal (MTN only) and without the distractions of life in the city. We were accompanied by our non-diving buddy Ian, who is a serious twitcher and brought his long camera lens to spy out the local birdlife.
There are three chalets at Marico Oog, only one of which has a toilet. Guess which one we chose. There is an ablution block for use by the inhabitants of the other two chalets (which do have baths/showers) and the campers – camping is allowed anywhere on the grounds. No appliances, cutlery or crockery are provided, so you have to bring just about everything including bedding. There are fridges in the chalets and fitted sheets on the beds but otherwise it’s quite rustic. I liked the thatch roof and the shady interior of the chalet, but Tony didn’t enjoy the occasional spider that passed by!
Facilities
Each chalet has a balcony area with a braai – the one we were in had a huge stoep and space for five to sleep in the same room. It’s the furthest from the water, but the walk is neither far nor demanding. There is a lot of grass to run around on (if that’s your thing), and the chalet we were in is well spaced from the other two, which are back to back. There’s a water slide on the grass left of left the middle of the map, but I’m not sure whether it’s functional.
Wildlife
Ian on the pontoon
The swimming pool (top right in the map above) was almost empty, which made for some lovely photographic opportunities. Ian found three mice (one dead) in the pool, and several frogs. To me the bird life was quite diverse, but there didn’t seem to be anything on the farm that couldn’t be seen elsewhere. Each evening we sat on the pontoon on the Oog and watched barn, white-throated and greater striped swallows coming to feed at the water and roost in the reeds. It’s very quiet and peaceful there, except for the inhabitants of the neighbouring farm, who share part of the water and seemed to enjoy fishing with beers in the evenings.
Diving
I am expecting a call from National Geographic about this photo
There are no compressor facilities at Marico Oog, so you have to bring everything you need. We rented cylinders in Johannesburg, one each. Because the Oog is at most 13-14 metres deep and on average more like 5 metres deep, you can dive for a couple of hours on a cylinder if you want to, so it’s not really necessary to rent a pantechnicon to transport your dive gear. The water is about the same temperature as False Bay in summer (19-22 degrees).
Path leading to the Oog
Approaching the ladder at the Oog
Ian on the pontoon
Access to the water is via a ladder, reached by walking along the left hand path you can see leading to the water on the map above. The right hand path leads to the pontoon raft.
Entrance to the Oog
Marico Oog water is bottled and sold as Vippita spring water.
Clare and I were away last week and despite the modern world in which we live we stayed in a place called Marico Oog that had no cell phone reception. In order to download text messages it required a drive of some distance to a hilltop for signal, quick replies and then back down the valley. Despite (or because of) the lack of contact with the outside world we had some awesome diving in the source of the Marico River, crystal clear water, 21 degrees and the nice part was diving with no weight belt!
Clare among the water lilies at Marico Oog
Prior to the trip up north I had a very busy stretch and it has been pretty much the same since we got back. The weather did not play along for Saturday’s dive planning but Clare and I did get a real early start and when for a boat trip at Zeekoevlei to test a boat. Very windy and very dark brown water but a very nice boat ride. Two hours later the boat stood outside in our driveway. Watch this space!
Recent dives
Sunday we had a very cold, clean deep dive in the Atlantic, chilly 10 degree water. I have been in or on the water all week. False Bay is still pleasant at 19 degrees and on my way to Simon’s Town this morning I counted no less that 30 fishing boats between Muizenberg and Simon’s Town. The bay is teeming with big schools of fish right now. The water is not all that clear and the last few days reports from Seal island and partridge point have been 2-4 metre visibility.
Basket star at 13th Apostle reef
Weekend diving
Plans for this weekend are not cast in stone as yet as I want to wait and see what the water looks like tomorrow after today’s strong winds and rain. It was not all that great today as there was a fair amount of swell and the viz was a low 2-3 metres. Hopefully the wind will have cleaned the bay up somewhat.
I have a list of people that have all indicated a keenness to dive this weekend so I will text everyone on that list tomorrow evening. If you haven’t been in touch and might want to dive, you know what to do.
Cape Town Dive Festival
Cape Town Dive Festival
The very first Cape Town Dive Festival will take place at the Cape Boat and Ski Boat Club at Miller’s Point, on 10 and 11 August 2012. Visit the website, think about participating (boat dives are only R100), and let me know if you’d like to do some dives with us on either of the days. It’s going to be a super event and the aim is to promote diving in Cape Town, something that we are very enthusiastic about.
Cecil, cave diver to be (he probably is one by now thanks to Buks Potgieter of IANTD) lent us this National Geographic production. It’s just under an hour long, and recounts an expedition to seven of the blue holes in the Bahamas. A blue hole is a kind of vertical cave, roughly circular. They often contain freshwater (light) on top of saltwater (heavy). The reaction between the two layers of water where they meet (called the halocline) eats away horizontal passages off the main shaft of the sinkhole over time. Sometimes there is a layer of hydrogen sulphide, created by bacteria and decaying organic matter, beneath which is an anoxic (devoid of oxygen) layer of water which preserves organic remains (bones, not flesh) with remarkable fidelity. For this reason blue holes are sometimes referred to as time capsules. The deep water is usually very, very clear.
Here’s a picture of the Blue Hole on Gozo in Malta, where Tony and I dived earlier this year. It doesn’t have a freshwater layer – it’s sea water all the way, but the top view you can see here illustrates what a blue hole looks like. Beautiful!
The Blue Hole on Gozo
The multidisciplinary research team shown in this special aimed to uncover the ancient history of the Bahamas, which no longer have any large predators (such as crocodiles) occuring naturally there. Aside from the diving (more on that just now) there’s a bit of palaentology, anthropology and archaeology to keep history buffs happy. Blue holes are currently the subject of muchreasearch, and as the narration in this special points out, rising sea levels threaten to flood the holes and destroy the anoxic conditions that make them such excellent preservers of the past – so there is a sense of urgency to the studies being conducted.
The diving, though, is mainly what interested us (and Cecil, I suspect). The footage inside the blue holes shows how beautiful they can be, with stalagmites and stalagtites in the side passages carved out by the halocline as the sea level changed. It also shows how treacherous cave diving can be – fine silt covers most of the surfaces, and even the pressure wave created by a diver swimming forward above the bottom of the cave can stir it up… Never mind a careless fin stroke or bumping the bottom!
Some of the diving was done on air and other gas mixes, using open circuit scuba with side mount arrangements to make the divers’ profiles wider but flatter. Other dives, to greater depths (both vertical and horizontal), were done on rebreathers. One of the advantages of a rebreather, apart from ridiculously long bottom time, is no bubbles, which is great for photography and for cave diving where bubbles can disturb sediment and even bring down bits of rock from the ceiling. One of the divers claims that 10% of all rebreathers sold have killed their owners (this is an exaggeration – according to DAN, only about 5% of diving fatalities are on rebreathers but one must adjust for the fact that open circuit is far more prevalent)… And that while she’s putting her kit together she thinks about all her dead friends who perished using these devices. If that was my state of mind before going in the water, I wouldn’t dive – the depression would kill me first! The divers go through a 40 point written checklist before they get in the water for a dive and are very, very careful about maintaining their rebreathers.
This is a beautiful look at the treasures hidden in places that many of us will never visit. The photography is wonderful, even if the narration is a little bit over the top dramatic (but we’ve been spoiled by the refined dignity of the BBC, I think!). It’s a little bit sobering from a diving perspective, but one can only admire people whose determination to break new ground and advance science leads them to the very edge of what technology can currently assist with.
There are some still photos from the special here (go and look – very lovely). An article on blue holes in the Bahamas appears here.
A while back Tony and I were invited to participate in promoting the James Cameron production, Sanctum, via our blog. Unfortunately the fact that we are South Africa-based seemed to have been overlooked by the marketing team, so nothing came of that (except curiosity, on our part, to see the movie when it was eventually released). You should note that in this review – as per my usual style – I will almost certainly reveal details of the plot that you might want to discover for yourself. If that’s the case, skip to the last two paragraphs.
This is not a movie for new or nervous divers, or those who love and care about divers but don’t know enough to know what to worry about (for example, my mother worries about rip currents off the beach when I’m diving…). It’s quite a graphic film and unremittingly tense, and almost every single one of the main characters dies, rapidly and shockingly.
The manner of death for each character is different, and to some extent it illustrated some of the ways in which caving and (to a lesser extent) diving can go wrong. Characters run out of air, accidentally cut ropes and fall to their death (using knives around ropes and hoses is a stupid idea), panic and drown, are crushed by rocks, get fatally bent… And so on. “Mercy killings”, interestingly enough, occur more than once. And the cast isn’t that big.
Particularly upsetting to me was the death that starts it all off. One of the female characters drowns after one of the hoses on her rebreather ruptures (she’d removed the unit and pushed it ahead of her through a narrow tunnel moments earlier). Buddy breathing with rebreathers is possible, if a bit tricky, but both she and her buddy were wearing full face masks. Buddy breathing with a full face mask is VERY tricky, because you have to pass the entire mask back and forth between the divers, each one clearing the whole mask (much lengthier than clearing a regular diving mask) before taking a breath. The person waiting for air has nothing on their face until their buddy passes the mask back, can’t see anything, and their nose is exposed to the water, which can easily result in panic. I didn’t realise that drowning can happen so quickly, and having to fend off your panicking buddy because (s)he’s going to kill both of you must be the most awful experience in the world. Watching someone drown, even though it was in a piece of fiction, was very disturbing.
Most of the movie is actually not about diving; the protagonists are exploring a cave system, some of which is submerged. Their aim is to find where the cave meets the ocean, and they do a lot of caving and a bit of diving (all with closed circuit rebreathers, which enable lengthy bottom time and have the added advantage of not generating any annoying bubbles during filming). However, the diving sequences were quite beautiful – the caves are magnificent, and I can see how intoxicating it must be to explore new, incredibly scenic territory. The cave diving was filmed in Australia, around Mount Gambier. (As an aside, one of the stunt doubles in the movie died in February 2011 after running out of air while exploring the same cave system). Almost the entire movie is filmed inside the cave system, and the relief when daylight is finally reached at the end of the film is incredible.
This is a thriller and should not be seen as representative of the average caving/diving expedition (if it was it wouldn’t sell half as many tickets…). The script is frequently beyond lame, but that’s not why you go and see this film. The underwater footage is mostly spectacular, the special effects are decent, and the production is very slick.
We watched it one evening in the cinema, in 3D nogal, dorky glasses and all, but you can get the DVD here if you’re in South Africa, and here if you’re not. If you want to know about the poem quoted in the movie, visit this earlier post about it.
