The normally tranquil world of fly-fishing is facing a two-pronged assault: from the forces of technology and, even worse, high fashion.
First came the outcry over the "yobs with blobs" - anglers replacing the fly with a hairy, fluorescent ball of artificial fibres that attracts indecent numbers of rainbow trout in double-quick time.
Then came the news that Karl Lagerfeld will be complementing Chanel's Sport range, which includes boomerangs, bicycles and tennis rackets, with a fishing kit. Costing £9,170, this designer rod and set of customised flies, each bearing the famous "double C" logo, threatens to swamp the sport with fashionistas in designer waders.
In the case of the blobs, no one doubts their efficacy. But the trouble is that they make all anglers equal. It's as if any pitch-and-putt joker was empowered to shoot a 65 at Gleneagles, or every tennis player deliver 140mph aces at will. It destroys the hierarchy and banishes the mystery.
It is my private shame that I have - albeit unwittingly - used a blob, or something so similar as to share in its iniquity. Resembling a small, luminous pink marble, the lure was given to me by a guide in
Slovenia. Its effect on the rainbow trout of those rivers was galvanic. Fish that had disdained my floating fly and ignored my carefully drifted nymph gobbled the blob. After a couple of encounters, I put it away, thinking that fishing wasn't meant to be so easy.
On the trout streams that I mainly fish - in Hampshire and Wiltshire - rules have evolved over the ages to protect what is seen as the integrity of the sport. You may only cast upstream (curiously enough the Americans, just as sporting as us, usually cast downstream). At various times in the trout season you can only use a floating fly, known as a dry fly. At others you may use one that sinks, as long as it isn't weighted to sink too fast. And so on.
Some of these rules - such as not being allowed to sever tree branches that interfere with casting - are perfectly sensible. But others have very little to do with so-called sporting behaviour, let alone the feeding habits of trout. And many of the most powerful are unwritten: in particular, the dress code.
Even though Coco Chanel was an angler, especially during her affair with the Duke of Westminster in the Twenties, her company's current creations would not be well-received among the fraternity.
The watchword for us is old clothes and stained waders: anything that's not at least a little shabby is considered very bad form indeed. My hat, for example, is a Chinese-made straw number in an advanced state of decrepitude. A friend has said repeatedly that it is the kind of thing Vita Sackville-West would have worn when showing people round the garden at Sissinghurst.
If my reflection on the limpid waters of the Test and Itchen were to sport freshly bought clothes, I would be regarded with the deepest possible suspicion.
And so we return to the fibrous blob: to use it would probably mean a life ban from one's club, not to mention the contempt of all respectable anglers.
It would be like turning up at
Palace garden party dressed in a jockstrap and a Viking helmet - or, indeed, going fishing with gear made by Chanel.
Downstream: Across England in a Punt' by Tom Fort (Century, £14.99) is available from Telegraph Books for £12.99 + £1.25 p&p. To order, call 0870 428 4112 or see books.telegraph.co.uk