A roar goes up from the crowd as the two nuns drift towards the raging waters, helpless in their open canoe. They plunge over the edge of the 12-foot weir, and the mob cheer as they are pitched into the frothing brown river, then dragged downstream into overhanging vegetation.
But this is not the watery end for some hapless missionaries in a 19th-century colonial backwater. This is Ireland, September 2001. This is the Jameson Liffey Descent, Europe's largest canoe race – 17.6 miles of paddling pandemonium, when more than 1,200 international canoeists race from Straffan in County Kildare to Island Bridge on the outskirts of Dublin.
The nuns taking their first swim of the day are, in fact, men, two of the race's huge contingent of charity paddlers, the Liffey's own "fun runners". Of the 1,200 competitors, 400 are competing for "places".
I'm paddling my first descent with Wade Sutton, a South African friend and experienced canoeist from Cape Town. There are 26 racing classes – we've entered the Touring Canadian Doubles: streamlined bathtubs paddled with single "blades" (of the sort Red Indians use to sneak up on cowboys). And our preparation has been intense. Intensely worrying. Our lone practice session was the night before – and with Straffan Weir, the first and largest of the 10 on the course, bellowing in the distance, our "suck it and see" motto is leaving a sour taste in increasingly dry mouths.
Our race guide is Kevin Horan, an instructor with the Irish Canoe Union and owner of the most deranged laugh I've heard from a man who still does his jacket up at the front. "Now, remember to bear hard right on Straffan," cackles Kevin. "If you go down the middle, it'll eat you."
Paddling to the start, against the current, is difficult in a boat built exclusively for comfort. The start line itself is chaos, as hundreds of boats jostle to form up in their respective classes. On the hooter, the race is led out by the K2s – double racing kayaks and the fastest boats in the field. Both K2 and K1 (single) racers sit perfectly still, moving only at the shoulders. (The quickest K2 will be home in under two hours.)
Throughout the world, rapids and weirs are classified on a scale of one to five: one is a ripple, five a raging torrent. And, hours before the race, the local water authorities release enough water to create "flood conditions", reducing the risk of injury caused by obstacles in the water. While the roughest water on the descent rises no higher than grade three, the inexperienced would do well to remember that you can drown in the bath.
And then it's our turn. As the last vessels cross the start line, boat 212 (that's us) turns into the current and heads for Straffan. Approaching the weir, Kevin appears ahead of us, signalling for us to tuck in behind. Suddenly, he drops from view and seconds later we follow him over the edge. "Shooting" the weir from the side gives us a perfect view of the large recirculating or "stopper" wave, turning back on itself and creating a bank of water several feet high.
The experienced kayakers hit the weir head on, at speed, using hard strokes to punch through the stopper. We reach the bottom with little momentum and the stopper knocks us hard sideways, turning us over. In a flash, one of the 30 or so rescue or "squirt" boats draws alongside. With the river moving quickly, the safety kayaker barks instructions: "Hold your paddle, grab my boat." Paddling furiously, he steers us to an eddy pool out of the main current and, satisfied we aren't hurt, returns to the churning soup of boats and competitors.
Kevin has seen our spill and is laughing his head off; but the next obstacle is far from funny. The Jungle is several miles of water, twisting its way through dense, overhanging woodland. "If you get stuck," warns Kevin, "try and get as many branches under your body as you can. Don't let the water push you under – then you're in trouble." As we enter the woods, fully-suited frogmen are seated in the branches over our heads, their fins dangling above the water. Moments later we pass an upturned K1, snapped in half and trapped under a root.
The river emerges from the woods into the picturesque Liffey valley, and negotiating the next two weirs from inside the boat raises our spirits. But the Liffey Descent's challenge to canoeists extends to stamina as well as skill, and after the intense concentration of The Jungle, comes the arse-numbing boredom of The Lake – two miles of flat, open water.
Our reward for completing The Lake is The Portage, a 500-metre, energy-sapping dash with the boat on our shoulders. We refuel using the Mars bars and bananas taped into the boat, glad of the energy boost and the chance to stretch our legs.
And then it's Lucan Weir, the one that's been troubling me from the beginning. Lucan's shallow bottom means boats must shoot it sideways-on, leaning towards the falling water and "bracing" with a paddle. Kevin leads us down and the instant he hits the bottom, the spraydeck on his boat caves in and his canoe sinks. But he is loudly insisting he has not "technically capsized" and, chest-deep in water, is paddling frantically.
Against our better judgement, or indeed any judgement at all, we shoot the weir nose first and brave 212 hits the weir floor with a crunch. Thrown forward, I look up and see Wade hanging across the boat's rear beam. Perched on our nose, we eventually topple into the river. Downriver, Kevin is waving his paddle over his head: "212," he yells triumphantly, "the men!"
We reach the finish, exhausted. The timekeeper's clock reads 4hr 26min. Inside a vast marquee, the prize-giving has already begun.
Mark MacKenzie flew to Ireland courtesy of Aer Lingus. Reservations can be made on 0845 973 7747 or by visiting www.aerlingus.com.
Details of descent and other white-water races can be found on the British Canoe Union (BCU) website at www.bcu.org.uk, or by calling 0115 982 1100.
Information on BCU accredited training courses, as well as canoe clubs in your area, can be found at the same address.
The Lagan Descent takes place in Belfast on the 28 October. Details, along with those for all races in Ireland, can be found on the Irish Canoe Union website at www.irishcanoeunion.com.
Entry qualifications vary from race to race. But to qualify for the Liffey Descent, competitors must have completed any descent in the preceding four years or completed three rough-water ranking races.
Do and don't
Do wear a crash helmet and buoyancy vest.
Do lift your knees and point your feet downstream in the water – it might prevent a broken ankle.
Do carry drinking water and high-energy foods – you'll need them.
Do take a bailing pump if you're racing in an open canoe.
Don't panic if you capsize – descent racing in the UK has a 100 per cent safety record.
Don't ignore others in trouble – they could need your help. Also, you could be disqualified if you don't offer assistance.
Don't let go of your paddle – you'll never find it again.
Don't forget to keep your mouth shut – river water near any major city is pretty revolting.
Don't ignore whatever safety instructions you're given.