Canyoning

n. sport that involves travelling down creeks or streams which are flowing very fast within a canyon and being carried down the stream while floating on one's back

Canyoning (known as canyoneering in the U.S.) is traveling in canyons using a variety of techniques that may include walking, scrambling, climbing, jumping, abseiling, and/or swimming.Although hiking down a canyon that is non-technical (canyon hiking) is often referred to as canyoneering, the terms canyoning and canyoneering are more often associated with technical descents — those that require rappels (abseils) and ropework, technical climbing or down-climbing, technical jumps, and/or technical swims.
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n. canyoning