It's the national August Bank Holiday, and it's a lovely, mildly foggy summer day in Llanwrtyd Wells, Wales. There's a crowd out in the country: photographers, journalists, tourists, drunks - all cheering on the hearty competitors at the annual town race. Through the swamp. Underwater.

Bog snorkeling is the granddaddy of obscure sports in this small Welsh town. In recent years, splinter groups have formed: underwater bog biking and even a bogathalon. But bog snorkeling is still the most celebrated. Every year, hundreds of people flock to town to watch snorklers struggle through the swampy muck. The challenge: navigate a 60 yard trench through the waterlogged peat moss. Snorkeling gear and flippers are required, wetsuits are not, but those who have faced the bog without them highly recommend the extra insulation. Conventional swimming strokes are also prohibited – organizers want contestants to both flail and linger in the muck.

Julia Galvin, a biology teacher from Kerry , Ireland, currently holds the woman's world title, having completed the challenge in two minutes and 36 seconds in 2004. She did this after she and her husband finished dead last in the Wife Carrying Championship in Finland . The morale of the story: if you don't find success in one aspect of your life, there's always bog snorkelling.