The common flounder or fluke, which can be found all round our coast in areas of sandy or muddy sea bed, is a remarkable creature. It starts life looking like any other baby fish, swimming upright with an eye on either side of its head. After a few days, it begins to lean sideways and sink to the sea bed; the left eye starts to migrate round to the right side of the face and by the time the left eye has completed the migration, the flounder is swimming flat with both eyes uppermost.

The ability to swim flat, combined with the capacity to change skin coloration to suit its surroundings, enables the flounder to lie concealed in sand or mud and prey on passing marine worms, sandeels and small crustaceans. Flounders tend to feed close inshore and are generally the first fish to be carried up estuaries by the flood tide. At slack water, flounders wriggle into the mud in the shallows to prey on their favourite food, peeler crabs, while they wait for the tide to turn.

History doesn’t relate who first trod barefoot on a flounder or realised, once he had recovered from the shock, that an accessible food source lay just below the mud. But for thousands of years people living near estuaries have trudged across the mud-flats at low tide, taken off their shoes, waded into shallow water and used their bare feet to locate them. Tramping for flounders was a particularly popular pastime along estuaries of the rivers that run into Morecambe Bay and the bays round the coast of south-west Scotland – Luce, Wigtown and the Solway.

One Sunday in 1973 John Kirk, a veteran flounder-tramper, was having a nooner with some friends at the Glen Isle Inn, the only pub in the tiny of village of Palnackie on the River Urr in Kirkudbrightshire. It was a glorious, summer day; the tide was out and conditions were perfect for tramping. John suggested a competition to see who could catch the biggest flounder, with a bottle of whisky for the winner. An idea evolved, as they splodged about in the mud, of organising such an event to raise money for the local RNLI.

The Palnackie Flounder Tramping Competition raised £45 for RNLI in the first year, and very quickly blossomed to become the Grande Internationale World Flounder Championships. This annual event in July or August attracted as many as 350 competitors from all over Britain, as well as aficionados from Russia, China, Japan, Europe, Canada and the United States. All ages could take part and there were cash prizes and trophies for the heaviest and smallest flounder, a much-coveted Ladies’ Cup and awards for juniors and children.

By day the shallows of the River Urr were filled with competitors and the mud-flats swarmed with children, blissfully wrestling in the goo or hurling mud balls at each other. In the afternoon there were barbecues and tug-of-war competitions and at night Palnackie bounced to music from live bands while the Glen Isle Inn did a roaring trade. The event was extensively covered by radio and TV channels here and abroad, by the local and national press and by sporting magazines in America and Australia. In the course of 35 years the Championships raised over £20,000 for the local RNLI. The 36th World Championships will not take place this year. The event has been stopped dead in its tracks – as many other small country events have been – by the increasing cost of insurance and decreasing availability of committee members.

There is obviously more to tramping flounder than simply walking through mud barefoot, so I asked Craig Parker, who organised the Championships for 13 years, to show me how it should be done. Flounder return from their midwinter offshore spawning grounds in spring to coincide with the peeler crab moult, and I met Craig in Palnackie at the end of April. To increase the likelihood of a decent catch we were joined by John Robertson, winner of last year’s event, Robbie Cowan and Wally Wright, both experienced trampers from Glencaple on the neighbouring River Nith, my son Sam and a mixed pack of terriers and gundogs.

We drove from Palnackie through lush wooded countryside for a couple of miles, until we came to the crest of a hill on a narrow peninsula overlooking the estuary of the Urr and a huge expanse of glistening black mud.

Here, some donned bathing trunks, others simply discarded their trousers, while I, hoping the water would not be too deep, rolled mine to the knee. Initial research into flounder-tramping indicated that the well-equipped tramper carried a leister or fish spear, sometimes known as a fluking pick or, in parts of America where flounder-tramping is popular, a gig.

I had one constructed by attaching a toasting fork to a 6ft ash shank and had spent some time knee-deep in the stream that runs through the farm, practising stabbing imaginary flounders. This, I hoped, would improve my chances of catching something on the day and minimise the risk of inadvertently laming myself miles out on the mud-flats in the face of a flood tide. However, when I unloaded the leister, Wally Wright explained that some years previously trampers had instigated a moratorium on the use of spears.

“You used them like a third foot,” he told me. “As you tramped, you pushed the leister into the mud beside you and that way, you might get one that you had missed with your feet. If you trod on one, you turned your foot slightly and shoved the leister in. Then you turned the spear into the current and water pressure held the fish on until you got hold of it. Other times, leisters were used to spear fish caught in a pool or one of the gutters. The trouble was, small fish were getting taken by accident. Now, when we tread on a flounder, we hold it down until we can get our fingers into its gills.” My leister, reversed, was used by Sam as a thumb-stick.

The mud-flats, once we had scrambled over some rocks and through deep gullies to reach them, were curiously warm and firm to walk on. They were also extraordinarily vocal, groaning and gurgling like an empty stomach while billions upon billions of cockles made strange, glottal, clicking noises. We were walking on a king’s ransom in seafood. “They badly need harvesting,” John told me. “There are so many, the layer on top is beginning to smother the ones below.” Reaching the channel of the Urr, after a slog of roughly half a mile, we formed a line a yard or so apart in about 2ft of intensely cold, muddy water and started to tramp.

Tramping is done entirely by feel; the water is so murky it’s impossible to see more than an inch below the surface. Successful tramping, as demonstrated by Craig, demands that your progress through the water – “the tramp” – be flawless: soft, distinct strides, lifting your foot a few inches clear of the mud, moving it forward a few inches and putting it down firmly. Shuffle, move too quickly or step off balance and the fish are away. If a stick is used to help you along, the point must be kept well behind your feet. The most difficult part, however, is to tread on a fish with your bare foot and not succumb to the overpowering human reaction to leap away. Every receptor in the brain will urge leg muscles to yank the foot back and it requires enormous mental effort to reverse the thought process and press down.

I asked Robbie what it felt like. “Gives you a hell of a fright the first time you tread on one,” he told me. “A big one feels like a thick, slimy sponge and the rough spine down the centre of their body can be pretty uncomfortable. There is always a certain amount of wriggling, but the extent depends where your foot lands. Tread on their head and they thrash about and the tail comes up to smack you on the back of the leg. Catch their tail and they generally wriggle free before you can get a hold of them, but if your foot lands square on their body they seem to know they are caught and eventually lie still.”

I have to confess, my “tramp” was hesitant in the extreme; there are more than just flounders lurking in the mud – eels for example – and I would have been much happier armed with the leister. Once, I felt something move in the ooze and let out a maidenly squeak. This was all the more mortifying when John, tramping beside me, stopped and casually reached into the water. After a bit of scrabbling and a muttered “gotcha, ye wee brute,” he pulled a flounder up by the gills. A little later, Robbie caught another, with much the same insouciance. Starting young, at an age when treading on something energetic and slimy holds no fears, is obviously the key to success. Robbie began tramping in the River Nith when he was eight or nine years old, passing the time while his father was haaf-netting nearby. Wally remembers the Fifties and Sixties when the village boys in Glencaple tramped for flounder on weekends through the summer and sold them for lemonade money outside the Nith Hotel. It was the Championships that got Craig, John and many of their childhood friends started at a time when flounder-tramping was losing its appeal to the young.

For almost four decades, the Grande Internationale World Flounder Championships raised much-needed money for the local RNLI but, perhaps just as importantly, they introduced several generations of small boys and girls to a historic country pastime when many traditional rural pursuits, once enjoyed by children, are being forfeited in favour of computers and electronic games. The fact that the Championships have come to an end is yet another example of how hard it is for such events to survive 21st-century busyness.