The rope is taut, water is tugging at your ankles and the cliff edge under your feet is like greased Teflon. There's only one way to go, and that's down.
Welcome to canyoning. If you ever fancied the thrills of caving while still being able to admire the view, this is the answer. Simply follow the course of a small river, coping with natural obstacles along the way, from boulders and deep pools to rapids and waterfalls.
The inevitable cold of the water takes your breath away, but it's the first big drop that concentrates the mind for all but habitual abseilers. Being lowered off a cliff is even worse when you're shin-deep in water, near a thundering torrent which will soon engulf you.
And that's the nub of it: this is a full-on experience. No extra batteries or qualifications are required, beyond the most basic level of fitness and a willingness to step into the void. For novices, all the tricky stuff is dealt with by the guide.
When the water hits, you can't think of anything else. Having a river empty its contents down the back of your neck while you dangle helplessly on a rope is shocking, exhilarating, violent. Now the unlikely process of erosion carving gorges through granite and splitting mountain ranges becomes comprehensible, even obvious.
Given their combination of meltwater and vertical drops, the Alps are ideal for canyoning. Spain is also riddled with good terrain and has the perfect climate; the UK's smaller mountains mean shorter sections of appropriate river, which is no bad thing for first-timers. Wales, the Lake District and Scotland all provide opportunities. Wherever you go, a bit of rain upstream can change conditions from tame to suicidal in a few hours, so be prepared to change your itinerary at short notice.
With a bit of experience some routes will be within reach of competent climbers, whose abseiling abilities will come in handy - controlling your own rate of descent rather than being lowered, sack-of-potato-like, is not only more rewarding but ensures the guide can't leave you spinning on the end of the rope for everyone's amusement, driven like a turbine by the relentless flow of battering water.
But for most people canyoning will remain a professionally accompanied adventure. Fast-flowing water and tricky terrain make safety the paramount issue, and then there's the required equipment: wetsuits and climbing gear in an alpine gorge make you look like Jacques Cousteau on the set of The Eiger Sanction; in milder climates lightweight, fast-drying outdoor clothing is adequate; climbing gear is still essential.
Footwear is critical: staying upright on submerged boulders will reduce the day's pain levels significantly. Water sports shoes such as Salomon's Exydro provide fierce grip and drain freely once out of the water. Drybags are essential for cameras and other precious cargo.
Gentler variations are, of course, available, cutting out or skirting round the sheer drops and making the most of natural aqua-zooms to sluice you along. You still appreciate the forces involved, but this time they propel you rather than batter you. You don't even need to be a good swimmer to go for a walk in a river - so go and find out what water's really made for.
Who to canyon with
Nigel Shepherd (01286 872393) guides canyoning trips at home and abroad.
Craft na Caber (01887 830588), Kenmore, Scotland runs a local trip.
Canyoning in Britain is often mixed with other activities - biking, walking, climbing - since the sections of river that can be tackled are relatively short.
Various operators run adventure sport holidays that include canyoning in the Alps and Spain: Tall Stories (01932 252002); Alp Active (01223 568220); Plus Travel (0171-259 1099); High Trax (01433 670186).
What to take
Climbing gear - helmet, harness, ropes, etc - available from climbing shops. Given the battering this gets, it's probably best to go with an organised group where equipment is supplied; the same goes for wetsuits.
For footwear and clothing, try specialists such as Ellis Brigham (0171- 240 9577) and Snow & Rock (0171-937 0872). Water sports boots are ideal; trainers will do. Lowe Alpine's Dryflo T-shirts and long johns have extra warmth and quick-drying properties. Lightweight waterproof clothing won't keep you dry but will reduce wind chill. Avoid cotton clothing - it stays wet.Reuse content