WHEN the elephants finish leaning on the ever-weakening walls of the bank in Kariba, they are wont to deposit themselves in the backyard swimming pools of various alarmed residents. It is said that the ultimate revenge on an enemy in this part of the world is to stash a bag of oranges under his car, thus ensuring that it turns turtle by morning. Kariba, the pretty 30-year-old town which burst to life as a construction camp for dam workers, is the main staging area for journeys on to and around spectacular Lake Kariba, one of Africa's greatest wildlife sanctuaries. Before 1960 there was no lake at Kariba, just the swiftly flowing Zambezi River, fresh from its dramatic plunge down the awesome Victoria Falls. Then on May 16, 1960, Queen Elizabeth concluded 10 years of labour by flicking the switch to start the giant generators attached to the 128-metre high Kariba Dam wall. By 1961 a giant inland sea had formed, stretching back 290 km from the wall and spanning 42 kilometres at its widest point. It was an engineering marvel not hailed by all. The native BaTonga people called on Nyaminyami, the River God, to curse the man-made abomination. However, their ire decreased in direct proportion to their sardine fishing income. And the wildlife recovered from its abrupt displacement. The world's attention was captured by Operation Noah, a mercy boat and airlift, helmed by game ranger Rupert Fothergill, of some 5,000 beasts (representing 35 mammal species alone) from isolated high ground to the shores of the Matusadona National Park. Initially shaken, the relocated animals - elephant, zebra, antelope, hippopotamus, lion, leopard, rhinoceros, crocodile, warthog, buffalo, gnu, and hundreds more - thrived on the succulent grasses which the new lake provided. Elephant, buffalo and large cats, normally averse to deep water, could be seen swimming between islands and shores, following ancient game trails with an age-old instinct. Birds flew in from all over Africa and even Europe to perch on the tops of now-petrified trees which had been higher than the lake's average 18 metre depth. Introduced fish, such as bream, chesa, sardine, vundu and tiger fish (up to 15 kilograms), thrived. Suddenly Lake Kariba was one of the most attractive travel destinations on the African continent. Up went the hotels, the safari lodges, the marinas and even a casino - all with good taste and a concern for the environment. The Club-Meders stuck to Caribbea Bay while the more discerning visitors sought out and gave international reputations to the prestigious, game-drenched lodges - Bumi Hills, Spurwing Island, Tiger Bay, Fothergill Island, Zambezi Resort and Water Wilderness among them. But for the truly astute African adventurer, there came to be only one realistic way to experience Lake Kariba, and that was by boat. At present there are at least 10 reputable companies chartering craft out of Kariba. These range from five-metre fishingboats to 20-metre luxury cruisers. Most are self-piloted, with all facilities and provisions included. There is no question that some of the best game viewing in Africa can be achieved from a floating position. My most memorable African experience was on Lake Kariba, bobbing in a power boat with its engine killed just five metres from three young but hugebull elephants - an unthinkable proximity on land. These proud pachyderms, who had swum over to one of the lake's many tiny islands, were trying to impress and intimidate us by snorting and squealing, stamping their feet and flapping their ears wildly. It was quite a floor show, culminating with the surprise appearance of a surly hippopotamus, who had wandered on to the scene to see what all the fuss was about. Upon his arrival our guide wisely powered up the outboard. At Bumi Hills Safari Lodge, overlooking the lake, I was regularly entertained by spider monkeys hurling themselves between trees. An early morning game drive down to the lake shore brought me close to a family of zebra, who dominated my total attention for more than an hour with their ceaseless skylarking. A light aircraft flight from Bumi Hills to Fothergill Island (undertaken after we had driven up and down the grass landing strip to frighten away any lurking animals) saw us sweep low over hundreds-strong elephant herds. From Lake Kariba, the mighty Zambesi is well worth exploring. Upstream is the imposing Victoria Falls, while downstream is possibly Zimbabwe's finest game park, Mana Pools. Part of the vast Middle Zambezi Valley wilderness area on the Zambian border, this is a wildlife park par excellence, a region of long cool alluvial woodlands interspersed with tiny glades and sun-dappled herds of impala. There are some 12,000 elephant in the park, as well as varied antelope, baboon, hyena, black rhino, leopard, lion, cheetah and buffalo.