if you think that ordinary bogsnorkelling is just a bit tame for you, then how about trying your luck at riding a mountain bike along the bottom of a 6ft deep water-filled trench cut through the local Waen Rhydd bog!
The bike used is specially prepared with a lead filled frame and water filled tyres to ensure grip on the pond bottom. The snorkeller/cyclist wears a lead weight belt to avoid floating off the bike! Divers are on hand for safety purposes.