A bumble is a cross between a bath and a ramble. The bath part involves immersion in the mostly clean waters of the river, jumping from the bank, sliding down weirs and crouching under waterfalls. The ramble involves crawling primeval out of the river on the soft mud banks, and staggering, dripping down the towpath, until a new entry spot is found and checked, then plunging in and floating downstream.
We meet our instructor on the hottest day of the year , trussed up in wetsuits, flotation aids and helmets, sweating quietly in the shimmering heat. Our sudden plunge into the River Stort by Harlow Outdoor Centre startles some of the local fishermen, and we slip one at a time down the slimy emerald weir, losing footing on the pebbled river bed, the placid green waters rapidly cooling our bodies as we float downstream, willows bent overhead and ducks fluttering startled into the reeds.
Bumbles could be a version of supervised wild swimming, with more equipment. Swimming in buoyancy aids isn’t easy, especially with trainers on your feet. We muddle down the river, small fish darting around the shallows, trying not to think of the Pike that may be lurking in the deeper, darker parts. A few minutes splashing takes us past narrow boats, where a small chimney leaks wood smoke and the owner sits on deck, his dog barking madly at this new breed of fish that dares to come so close. A fisherman tuts as we pass, smiling and waving.
A shallow beach under the shade of an overhanging tree is the place we attempt to climb out, gripping the branches and each other in a sliding, ungainly dance until we’re all safely on the towpath, water dripping from every orifice. The instructor walks us up to our first jump of the day, from a bridge joining one footpath across the water to the meadow beyond. This goes against all sensibility, and is the complete opposite of all we tell our children not to do – don’t ever jump off bridges, you could break your legs landing on hidden rubbish in the water, or shatter your spine in the shallows. We consider these options as we peer over the railings to the softly stirring water below, a long way below. Trusting in the expertise of the professional, we let the instructor drag a chain across the riverbed, till we’re all satisfied there’s no lost Asda trolley lurking there. Just to be sure, we let him take the first jump. Eventually, we all follow, hearts in mouths, flinging ourselves into the air. Time pauses for a second, then a splash and a lunge under, glimpses of muddy water, ears filling, noses overflowing with river water, clenched into a ball, bottoms bumping on the muddy bottom and bouncing up to the surface, swimming for the bank to scramble out and do it all again.