I looked forward to diving in Lake Tanganyika. Long and narrow, it stretches down from Bujumbura, the capital of Bujumbura, to touch on Zambia in the south, Tanzania to the east and, in the west, Zaire, whose purple mountains plunge deep into the lakes inky waters.
At 1435m, Lake Tanganyika is the second-deepest lake in the world, after Lake Baikal in Russia. Not surprisingly, its waters are the source of many a dark African myth; but my mind turned to more immediate things as I collected diving gear from a Bujumbura dive centre and headed south with the centres Belgian instructor, Guido, and Helena, another visitor from Sweden.
I had heard about the lakes tantalising, colourful fish, some of which are exported to Europe; and that it is the only known lake environment of the aquatic cobra. But one fact which gripped me was that, diving in shallow waters close to shore, you have a pretty good chance of coming face to face with either a crocodile or a hippopotamus. Mmm. Out of the water, the hippo looks so clumsy, almost adorable. Taking evening drinks on the lakes shore in Bujumbura, we watched them emerge from the water, nostrils first, their beady eyes scanning before they lumbered ashore. Crossing the nearby road and causing traffic jams, they are a regular attraction, their tiny ears whirling and fat little pillar legs supporting a massive, rotund body.
A hippo trail shows as two deep ruts made by the feet - and a dip in the middle made by its dragging belly. But that is on land. The water is their domain, where they can drift silently through the glassy calmness, yet easily outswim a diver. We were to learn all about it.
I had been assured by Guido and the expatriate diving community that hippos never attack divers. On the drive south, Guido repeated: In the 15 years Ive dived here Ive never seen one, so relax.
If anything, it seemed to be crocodiles you needed to look out for. Kitting up at the waters edge after our 49km, pot-holed drive, Helena and I were told not to hang around standing knee-deep, as a croc could lash out with its mighty tail and break legs; and not to wait for our buddys OK signal, as an arm could be too tempting!
And before returning ashore, Guido said, we should scan the waters edge for crocs basking in the sun. Hippos, then, had departed from my mind as we entered the water.
Twenty minutes into the dive, at a depth of just 4m, I felt relaxed. The water was murky, but I had enjoyed watching schools of catfish darting around the boulders, and had even freed some of them caught in abandoned fishing lines. Guido was close by, while Helena was a little way behind us.
Suddenly, a faint but solid grey wall materialised, blocking my path. I stopped for fear of colliding with it. Then, slowly and deliberately, it turned away, two stubby legs clearly attached to the mass as it moved out of sight. I knew that I was in the wrong place at the worst of times, yet a surreal calmness took over as the reality of the situation hit me.
Guido signalled to me to surface, and we rose together. Helena, too, was on the surface some way off. Clearly she had seen the hippo too, and began to make her way back towards land.
Guido and I also started to swim towards the shore, which lay some 20m away, across unnervingly tranquil water. The hippo seemed to have disappeared, but the tension was almost unbearable as I turned every few seconds to check out the water around us.
My neck muscles started to ache, as I had no BC to support my cylinder, and I started to tire. Guido beckoned me over, took me into a rescue position and we made our way slowly on.
Without warning, out of the stillness, it came. A deafening roar, a mouth wide open. Oh my God, its happening! This is it! A massive body heaved up out of the water and the hippo pushed its tusks at Guidos lower legs, raising him partly out of the lake. I dropped from Guidos hold, and watched in disbelief as he was shaken violently, like a rag doll, before the hippo disengaged and retreated.
Guido, his legs hurt, was still able to struggle towards land. I gathered my own strength, trying to ignore the pain that ripped through my neck, and focused on the shore ahead. It was reedy, and it occurred to me that crocodiles might lurk there. It was a risk I was willing to take.
The shore was not far off now, but how long might it be before the hippo attacked again As I thought this, and despite my senses being on full alert, I was barely prepared for what happened next. I was expecting it, yet could hardly believe that it really was happening all over again.
A wild, terrifying roar shook the air as the enormous grey body smashed out of the water once more, a few metres away. Right, Im going to die. If Im bitten in half, please dont let it hurt. Go for the shore, do your best to make it, but if you dont, well, that will be the end of it.
But it was Guido who was attacked again. With its jaw open wide, the hippo heaved three-quarters of its bulk out of the water. I watched, frozen in horror, as it took one of Guidos legs wholly in its mouth and lifted him completely clear of the water. It spat him out and, as before, disappeared back below the surface.
Suddenly I felt large boulders beneath me, solid and safe. I looked over and could see Guido, with an astonishing rush of strength, already staggering ashore. Minutes later I, too, struggled on to a pebbled beach and collapsed, my legs feeling like perished rubber.
I lay motionless, soaking up the warmth of the stones, before two African men - among locals who had gathered as the deadly drama unfolded - arrived to help me back to our jeep. I couldnt think or talk and, head in hands, collapsed on the bonnet. It felt so wonderfully warm. Slowly I returned to the reality of my surroundings.
Helena was there, and Guido was already being helped into the jeep. His wetsuit hid the full extent of his injuries, but he was losing a lot of blood and his skin had turned a pale shade of blue-grey. He remained in cheerful spirits, possibly a defiant reaction to shock, during the dash to the nearest hospital at Bujumbura.
Guido was to remain in hospital for five days, as four wounds in one leg were treated. Severed muscles and broken skin had to be stitched, and antibiotics were lavished upon him to resist gangrene. At one stage his temperature rose, but stabilised again.
All in all, Guido was fortunate not to lose his leg. In fact both of us had been fortunate to get away with our lives. Hippopotamuses kill more people in Africa than any other animal.