"Go right," I yell, thrashing the water with my ineffectual paddle. "I'm resting," my husband, Rob, says mutinously. We are zigzagging crazily along the Zambezi, one of Africa's wildest rivers. A hippo pops up behind us - we have canoed directly over him.
Meanwhile, our four friends, skilfully executing their mysterious C-strokes and J-strokes and sweep strokes, are motoring along some distance away in the correct single file, neatly "threading the needle" between two territorial hippo pods, the just-calved cows particularly vicious.
We are six middle-aged city dwellers living the dream of wild adventuring in deepest Africa; however, it is taking some adjusting as we learn of the many ways Africa can make you suffer - cerebral malaria, bilharzia, tsetse fly, man-eating Nile crocodiles, columns of giant Matabele hissing ants, not to mention ominous stories of lion, elephant, crocodile and hippo attacks. One of us also has an irrational fear - of the bilharzia fluke burrowing into an, ahem, intimate appendage - dubbed "willyharzia". But what is life, after all, without a little feral excitement?
And so, after one canoeing session on the hippo-free Lane Cove River, we have arrived in Zimbabwe's World Heritage-listed Mana Pools National Park
, 2000 square kilometres stretching along 80 kilometres of prime Zambezi riverfront, part of Africa's ancient Great Rift Valley. This is one of Africa's last great wilderness areas, game-rich beyond belief as the waterholes and streams evaporate in the June-to-October dry season.
Seeking sustenance, the great herbivores and predators descend from the woodlands of the rift escarpment to the mopane thickets and rich alluvial riverine terraces, shallow pools and flood plains of Mana Pools, which means "four pools" in Shona. These are the perennial pools or oxbow lakes, remnants of the old riverbed that runs parallel to the main channel. The pools and river provide rich, dry-season pickings for prolific game and birds and are part of the 400-square-kilometre, 35-kilometre-long Mana flood plain where our safari operates.
Here, 15 degrees south of the equator, tropical moisture and heat yield a rich, dry-season smorgasbord of sweet grasses, mopane, sausage trees, baobabs, Natal mahogany and the protein- and mineral-rich pods of the winterthorn (acacia) tree - "the magic time of the pods", as our guide, Mark, puts it. It is animal heaven - human, too - for those lucky enough to visit.
And we are lucky, despite our initial abject terror or, as Mark tactfully says, "adrenalin moments". Is there a glimmer of mischievousness as he briefs us before canoeing, shortly after we have signed the form accepting full responsibility for our potentially imminent demise?
"Hippo can move 20km/h under water," Mark says. "It's important to canoe quickly through their territory, single file. The last hippo strike was seven days ago when a hippo 'banzaied' off the bank between two canoes." Hippo strike? "If this happens," Mark continues, "you roll in a ball and float down the river until rescued."
A hippo looks silly - a simple, 3000-kilogram vegetation-distilling vat. But when they expose their incisors, all the better for biting, they aren't silly at all. It is we who are silly: silly with terror at Africa's greatest man-killer.
Then there are the prolific Nile crocodiles (100 counted in 50 seconds). Mark says they "eat more people than salties". You never go near the water's edge, keep the canoe between you and the river, keep arms inside boat - a girl was yanked out when her jumper trailed (she survived). If a croc attacks, whack it with the edge of the paddle. Is it comforting to know they mostly only take fishermen with bloody equipment?
What is comforting is that Mark is our guide. He knows Mana Pools intimately, a river and land guide with 25 years' experience who "relies on visual cues and references as the river changes weekly". And learner guide Takesure is almost qualified. He grew up fishing on the river, learning from his ranger father.
It takes 1000 hours' "bum on seat" to qualify as a river guide and five years as a land guide, and Zimbabwe's guides are some of Africa's best. Mark carries a powerful .460 Weatherby Magnum rifle plus a Smith & Wesson .44 Magnum revolver, both unused on animals. He and Takesure are geniuses at manoeuvring the 5.5-metre-long Canadian-style two-man canoes with backrest seats.
Jokes aside, Mark is correct to be frank. Our lives are in the guides' hands and people do come on the river ill-prepared.
"It is not just a sedate trundle down the Zambezi," he says. "My advice is to be fit, find a canoe and practise beforehand."
And there are solutions for strugglers. Canoeists can be rotated through the front of the guides' canoes - front paddling is relatively simple compared with the back steering position. Guides can tether canoes to rest people, and can install a non-paddling third seat. Extra guides and canoes can be added - in our case, camp manager and almost-guide, Elijah, who tells us how a hippo once dragged him and his companion into the water after they accidentally pitched their tent near a "hippo highway".
Our problems more or less sorted, we are able to begin the incredible experience of paddling Mana Pools, staying in four mobile tented camps and exploring by canoe, on foot and in game vehicles.
Planning this trip is complex. Liz Ferreira from Zambezi Safari and Travel Company is an African expert based in Kariba in Zimbabwe. She plots our safari, including our long journey into the park by air and road via Lusaka in Zambia and Kariba, spending necessary refreshing nights at Lusaka's Taj Pamodzi and Kariba's Hornbill Lodge
has operated on the Zambezi for 25 years and runs both Explorer canoe safaris (semi-participatory) and Odyssey (fully backed-up comfort). We choose the Mana Pools Odyssey Shoreline Safari, a four-day, three-night mobile-tented safari, with three days afterwards at Natureways' Zambezi Camp, where guests can do more canoeing, walking and game driving.
Mark and Takesure meet us at Mana airstrip and drive us to Vundu, our first tented river camp. All camps are mobile - no trace must be left on this pristine environment. This is our first look at the river, which is broad and fast-flowing - about six kilometres an hour - good news for bilharzia worriers as the fluke prefers still, shallow water, but confronting for amateur canoeists. Across the river are the Zambian rift escarpment's pink-and-blue misty mountains, which rise to 1000 metres and will become our constant companion.
Looking at all this majesty, we wonder how long it will last. Bizarrely, Zimbabwe has just granted a prospecting and exploration licence to mine for heavy mineral sand deposits here.
Evidence of a well-run camp is everywhere - beautifully erected tents on the riverbank (is that hippo dung? Yes) and table set with pre-meal drinks. Friendly staff include skilled bush chef Nelson, who creates three-course masterpieces over fire in cast-iron pots - delicious soups and entrees, mains such as roast pork with crackling and beef stroganoff, fresh bread and desserts including lemon meringue pie, banoffee pie and creme caramel, all lit by candelabra and delightfully introduced and served by Knowledge.
Our canoeing begins upstream and we bumble towards sundowners, blaming the slight wind for our incompetence. Tomorrow will be better, we tell ourselves as the African night comes alive.
We retire to our tents with only mozzie nets between us and raucous Africa - a cacophony of chugging and backfiring hippo, wailing hyena, soft elephant snuffles and the eerie sound of lion - very close. You never leave your tent at night, and have a chemical toilet attached. It is almost too exciting to sleep, and I watch the moon set red over the Zambezi and the stars slewing across the sky.
Hot water and a wake-up call arrive with the dawn. It's cold, single figures overnight (Knowledge supplies hot-water bottles), but temperatures can rise to the high 20s. We will "canoe" about 20 kilometres today to our next camp, Chessa, bumping banks, spinning, exhibiting the bane of guides - hippo fixation - "paddle fast, hit bank". Gradually, we learn to cope.
As we calm, we begin to observe the life of the river - the remarkable bird life (more than 400 species), elephant, all variety of antelope, warthog, zebra, everything here but giraffe and, sadly, poached-out rhino. Game numbers will triple by August as the area dries towards October's "suicide month", when temperatures top 50 degrees.
We stop regularly - for game walks that show an unfolding ecosystem story at your feet and which include two close lion encounters, elephant mini-charges, the hint of leopard, buffalo and the trails of dozens of crocodiles moving from drying waterholes to river.
Mark generally avoids the tsetse-fly-loving mopane, sticking to the flood plain, sometimes taking us through the aptly named "adrenalin grass", or vetiveria, while the rattling pods of cassias keep those spine shivers coming.
Riverbank lunch spreads include quiches, chicken pies, salads, cheeses, fruit and drinks, alcoholic too, for Dutch courage. Muscles ache as we head for those campfire sundowners, torn between watching Africa's best sunsets or scrambling for that twilight shower - no one wants to be lion food. Torches are mandatory, as is insect repellent, as this is malaria territory. No one is bitten by mosquitoes or tsetse flies, though a Matabele ant bite makes me yelp.
All up, we will canoe 50 kilometres, walk 20, and do many game drives. At the third camp, Illala, a croc swims past our tents, an impala in its mouth, while at Croton, our three-day Zambezi camp base, we track a mating lion pair that settles within earshot, close enough that I fumble the soap and ponder the effectiveness of a canvas-bucket shower.
This is Africa in the raw, well out of the comfort zone but deeply thrilling. Mark says: "People should be forewarned: it's not just a safari, there's dangers."
But perhaps that's why wild adventure tourism is on the rise. Inside each of us lies the explorer gene waiting to burrow out about the same time the bilharzia fluke burrows in.