I have been toying with the concept of a coarse angling version of the legendary hat- trick that earns such fabulous bragging rights in pubs and bars from Kelso to Cancun. But unlike most of my ill-fated ideas, this one actually came to a marvellous fruition one balmy summerís day this year.

The basic principle is pretty simple: Choose three species of fish, residing in local waters, which (if caught within a 24-hour period) will impress fellow anglers so much that they will insist on buying copious quantities of fine ale until well past closing time. Ironically, that simplicity soon evaporated when I came to present the challenge to a couple of angling friends over a glass or two at the White Horse. After a short debate over the benefits of split cane over carbon fibre, I broached the subject of the coarse McNab.

"What are you going to call it?" Asked The Captain, not unreasonably.

"Errm. Well I havenít given it much thought," I replied. "But I was toying with ĎThe McKnobí. Like a McNab only more coarse."

Actually, I had given the matter of nomenclature a great deal of thought, but I didnít want my friends to pour scorn on the fledgling idea before it had a chance of getting off the ground.

A heated discussion began, mainly centred on the fact that my thinking was demeaning to coarse anglers and stupid, although with the passing of time they gradually came to accept the term. In any case, we had more pressing concerns to debate.

Which fish should we be trying to catch? This was a point for tremendous argument, but I was ready with my own personal opinions: A barbel, definitely: Big, fierce fighting and a test for any angler. We agreed unanimously. A tench, possibly: The quintessential summer fish, beautiful, large enough to look impressive in a trophy photo and inhabiting different waters, generally speaking, to the barbel. Some discordance greeted this proposition, but not to any great degree. Then perch. What? Perch, for goodness sake? No, no, no, said the committee. You have to have a carp, no a pike, no a roach, no aÖand so it went on.

Eventually, I had to put my foot down.

"Look, itís my McKnob and I want a stripey!" I said, unfortunately just a little too loudly and, as is always the way, just when the surrounding conversation in the pub had died to a whisper. Several sniggers could be heard from other punters, not least of which was a party of American geezer-birds on the next table.

Not to be distracted, we encountered our next problem:

"How big?" Asked Flatus of Whiteparish. "Itís easy to catch a tiny perch. You have to set a size limit."

"I donít think size matters." I responded.

"Yes it does," called the nearest geezer-bird, much to the crude merriment of her mates.

Unfortunately, most of my friends tended to agree that size was indeed important, so we set our limits at an achievable, yet testing level. The barbel, we decided would need to be 7lbs or more. This weight was chosen not so much because it has any magical quality (unlike a ten pounder, say), but because barbel do seem to have an ideal fighting weight on the rivers we fish. Anything between 6 and 8lbs, the fish seem to be at the peak of condition, capable of wrenching the skin off your arm with the first tearing run and marvellously fit in every way.

The tench was entirely harder to weigh up in our minds. There are those who consider a five pound tench to be a fine achievement and I have to admit that Iím one of them. Then again, I know a lake just outside the M25 where clever anglers catch tench twice that weight and more. Itís a moot point of course, because a trophy fish is only as big as the water allows. A tiny farm pond stuffed with stunted tench might produce a two pounder and the angler would be justifiably chuffed to bits.

And, to make matters more complicated, The Captain kept muttering that he didnít approve of all these modern weights and measures (he hasnít yet woken up to EC laws on metrication) and wouldnít it be better to have a gentlemanís agreement instead? Finally, I had to call the meeting to order.

"A big one," I said in firm tones, "shall weigh not less than five pounds."

"Phwaooor!" Went the geezer-birds. We ignored them studiously.

Perch are equally difficult to gauge, but at least two of us held the strong belief that any such predator over 2lbs in weight must be considered worthy of a brag or two, even though the angling press seems to be filled with three and even four pounders these days.

And so the seal was set on an adventure, which I am happy to recount.

The day in question began inauspiciously, when Nick The Soup failed to bring his chest waders to the Great Pond and was forced to strip to the waist in order to get out to the famed ĎPlatform Swimí, pre-baited the night before with an entire bucket of worms, sweetcorn, hemp, casters and bread. Nick was a brave man, despite my direst warnings of parasitic worms capable of swimming down small apertures and causing untold havoc in a personís soft organs.

Thankfully, the tench did not object to the entirely awful appearance of a half naked man in the lake and were already fizzing happily in our swim. With indecent haste, we tackled up, threw out our quills, fully expecting immediate action, although, as is so often the case in fishing, we were not anticipating what happened next. The floats did indeed rise and sail away, but not with the attentions of fat, yellow bellied tench. Instead, we caught perch. Great big perch, two of which easily topped the two-pound mark. Then all of a sudden, the perch went away and we began to catch rudd. Glorious, golden rudd with perfect scarlet fins, nearly the same size as the perch and quite as lovely. The extraordinary thing about this hectic hour-and-a-half of fishing is that until this season, the Great Pond had kept its fabled perch and rudd completely hidden from us. We had caught dozens of large tench, sometimes with embarrassing ease, but only a tiny perch or two had ever come to our nets and certainly none of the big rudd.

Of course, the appeal of the McKnob rapidly disappeared from our thoughts as we set about emptying the lake of perch and rudd, until at midday, Flatus of Whiteparish exclaimed:

"Bloody hell! This is a big one!" A green spade of a tail surfaced over an enormous swirl and with a screech of the centre pin reel, we knew that this was a tench straight out of our dreams. A minute or two later, Flatus landed the most portly, pregnant fish I have ever seen, weighing exactly 7lbs in weight and heralding a short frenetic feeding frenzy in which we caught three others, smaller but far fitter tench that stripped line off our reels to hoots of excitement. By lunchtime, the spirits of the lake threw the Ďoffí switch, the fizzing died away and all went quiet.

Flatus had completed two thirds of the McKnob and I (with a perch of 2lbs 2oz and a tench of 5lbs 4oz) claimed the same.

Under normal circumstances, with the sun high in the sky and the fish lying torpid until evening, we would have packed and made our way to the pub for a slow celebration of the morningís events. However, with the capture of both big perch and tench, the McNob had become a distinct possibility and our interest was renewed, so we made our way to the river Kennet, near Aldermaston. Nick, with a sullen wave, departed for an afternoonís work.

The Kennet has become my absolute favourite river over recent years, since, unlike its bigger sister, the Avon, which I still adore, I have found it far more obliging. Every bend seems to have a channel, pool, or overhanging willow, easily identifiable as a barbel swim, chub hole or roach glide. And although the barbel are probably smaller, they fight with such ferocity that I really couldnít care less if they are a few pounds lighter.

The swim we chose, after a fair old walk through a nightmarish jungle of shoulder-high nettles and willow herb, had everything a homely barbel could possibly desire. Fast water entered a deep channel, flowing right under a huge fallen willow tree on the far bank and underneath, clean gravel on which to feed. The only discomfort was a squadron of blood-thirsty mosquitoes, that left swollen bites the size of tangerines.

We swatted and swore at them as we tackled with simple ledgers and lumps of Spam. Since the Kennet is so narrow for most of its length, the favoured method was to use a lightish Avon-style rod, in my case a cane Chapman 500 Deluxe, modified by the master craftsman Tim Watson, married to a Witcher Aerial centre pin, definitely the most heavenly reel ever created by man. Unfortunately, most people will never have the chance to possess a Witcher reel, because the maker, Paul Witcher, only ever produces a handful each year. But if, like me, you feel that the riverbank is somehow incomplete without the loveliest Ďpin that money can buy, you might like to give him a call (tel: 01428-717945).

To digress for just a second, I must mention that I donít necessarily hold with the more extreme values of the traditionalist movement in angling, where people would rather not fish at all than use an item of modern tackle. It seems to me that there is a fine line between enthusiasm and fanaticism. The more important point is that a stick and revolving drum appear to sit among the water mint and cow parsley a little more elegantly than anything else.

Which brings me to the last leg of the McKnob adventure. My bait had barely settled under the overhanging willow (a tricky cast upstream, allowing the weight to trundle along the flow and with fingers crossed that no submerged branches would snag) when the rod tip knocked once, then hooped over with the unmistakable first run of a muscular barbel. Iím sure that a good carp, or a salmon will fight with even greater strength, but for some reason there is a fantastic thrill about the surge of a big barbel. I think it must be something about the setting, so gentle and intimate, in a soft English way that an explosion of energy appears out of all proportion.

The barbel weighed 7lbs 2oz. In purely practical terms it was no monster, but from the Kennet a good fish and in the context of our plan to catch the McKnob, a truly happy occasion.

Judging by the reports in my fishing diary of the last few years and in the classic way of all fishing tales we should have caught no more fish at all. But the sport didnít end there. Flatus, irritatingly, caught a larger barbel, by a pound or so, followed by another of about 6lbs then I landed another, smaller still and finally a modest chub.

We had achieved not one, but two McKnobs in a single day. Some might say with reason, that we set our sights too low and they are probably right. But the moral of my story is that the challenges we set in our fishing donít have to be about personal bests, or record fish. We can be creative about our goals and have just as much fun with them. In fact, I donít think the McKnob is important at all and I still agree with The Captain that size doesnít matter, despite what the geezer birds say.