Lets start from the beginning…
The African continent is considered one of the oldest crusts on earth. So you expect to see a rugged topography such as observed in North Africa (the Atlas Mountains) and (the Drakensberg Mountains) in South Africa. However the landscape in Ndola Zambia is different. You see rolling landscape and nearly flat topography. But geology may explain this…
Limestone is a calcium bi-carbonate rock made from calcium-rich sediments deposited in deep seas. Yes, Zambia right in the middle of Africa was once a sea in the long distant past. But I digress…
Being calcium-rich limestones dissolve easily in acids. Rainwater tends to be acidic even if mildly so due to carbon and sulphur in the air from burnt forests, grass, coal, etc. Decaying carbon also adds acid to underground water.
Over the years the acidic water has dissolved large amounts of the limestone rock and formed water channels (under ground rivers). This chemical weathering has also eaten away at the base rock below the soil cover leaving it rounded off. In many places this process has created caves everywhere.
So the landscape takes on a rolling surface and rivers traverse everywhere. The land becomes devoid of hills but sunken water reservoirs become common place. Some of them are quite large. Thus how the sunken lake of Kashiba and others strewn in the surrounds of Ndola have came about.
Almost invariably the underground rivers feed these lakes. So the lakes don’t dry up in after the rains stop. It’s from one such lake where the scene of the scuba diving challenge… the challenge that no one has ever been to the bottom of Lake Kashiba .
This challenge has been attempted and successfully accomplished too. Before Neiles Billany became a North Sea diver he took on this challenge. This served as his first scuba diving lessons. And he remembers with nostalgia those of his friends, colleagues and the times…
In his own words Neiles Billany explains this feat, the challenge of Lake Kashiba...
“When I was a young man in Zambia (I was born in Mufulira town, my father was a miner) I took up scuba diving. There was no club in Mufulira so I joined the Chingola club. ( Editor’s note: all these are towns on the Zambian Copperbelt). After a while there were a few members from Mufulira and Kalalushi and we dived extensively in the sunken lakes ; Kashiba, Ishiku, Chilengwa and Mpambu.
Kashiba was the biggest and deepest and a challenge to reach the bottom. We had some members who were surveyors and using a rubber boat we took the soundings of the lake. As you know the lake was formed by the collapse of a limestone cavern. The south side turned out to be the shallowest end at just over 70 metres (the lake was not full, probably 6 to 8 metres from being full). ( Editor’s note: the water surfaces of sunken lakes tend to be below the surrounding land surface and so great for scuba diving lessons).
We had some shallower readings of about 50 metres but these turned out to be huge blocks from the collapsed sides of the lake and not the bottom. The lake sloped steeply downwards towards the northern end were the depth exceeded 150 metres. Explorations around the edges at dives of up to 40 metres showed that at the northern side the cavern continued underground.
We knew that the deepest we could reasonably go with scuba equipment was 50 metres and even this was dangerous as there were no decompression facilities in Zambia. We did some exploration dives at the southern side, then on November 15, 1975 Werner Hock a German engineer and Alan Vaughan a British technician dived to the bottom with Bill Gellately and myself covering them at 35 metres. They landed on a huge block at 50 metres, and then descended from the block to the bottom at 73 metres.
The following year on October 24, 1976 (Zambia’s Independence Day) Frank Ingram a British engineer and myself repeated the dive at the same spot. We landed on the same huge block then descended to the bottom which was very muddy and covered with many beer bottles and cans (what a shame people are so careless).
In 1977 I travelled to Britain and trained as a Commercial North Sea dive. I worked for many years in the North Sea. With hindsight I realised that what we did with the equipment we had was very foolhardy and dangerous and I would not recommend that anyone attempts to dive to the bottom of Kashiba as they could lose their life. I would not dive to the bottom of Kashiba again, not even with North Sea equipment; maybe the water spirit was kind to us all those years ago but I would be more respectful today.”
And luckily Neiles remembers some more of those juicy ‘fairytale’ like stories of the long gone days...
“A year or more before Werner Hock and Alan Vaughan dived to the bottom of Kashiba four members of the Chingola Sub Aqua club attempted it. Although they were well prepared they were badly affected by nitrogen narcosis and had to abort the dive. They were lucky no one was injured or died.
Scuba Diving Lessons
We learnt from their experience and prior to Werner and Alan's success Frank and myself spent the weeks before building up our tolerance to depth diving in Lake Ishiku. We took our scuba diving lessons at Ishiku, which had a depth of 60 metres when full. At Kashiba we did a couple of 50 metre dives in the days before the attempt to the bottom. This increased the resistance to narcosis. We also had backup divers and spare aqualungs on the shot line.
So we were not completely foolhardy when we jumped straight into the lake. We were very experienced and took preparation over some months before each attempt. If anybody wishes to attempt it I hope you pass on my advice. They need to be experienced, fit, well prepared and build up a resistance to narcosis or they will put themselves to their peril. To reach the bottom of Kashiba is not an easy thing to do.” ( Editor’s note: but the challenge still stands…)
And here is Neiles’ advice…,
With hindsight Neiles now knows what he and his buddies should have done to be equal to the challenge of scuba diving. It requires specialist equipment using heliox mixture (helium and oxygen) or tri mix (helium, oxygen and nitrogen). There are specialist trimix closed circuit (the exhaled gas is filtered to remove CO2 then fed back to the diver) scuba diving sets now available and these would probably allow a diver to reach the bottom at 100 metres! ( Editor’s note: wow! Take note of expert advice).
Zambia African Safari © ZAS 2004