As far as I'm concerned an 18" Bowie knife has very little to recommend it here in Britain, or for that matter anywhere else in the world: in fact, if you're daft, and macho enough to try toting one around, you're likely to find yourself enjoying a spot of free accommodation - courtesy of Her Majesty. Still, when it comes to knives and their uses, we Brits can learn a great deal from our American cousins. The ownership of a useful knife is all part of an American boy's rite of passage, and a simple design, but super-quality, Buck pocket-knife, received on a fourteenth birthday, might well be passed on after a lifetime's use, perhaps to a favourite grandson.

In Britain, we seldom find it necessary to hack our way through impenetrable mangrove swamps in order to reach our swims. So cultivated is our angler's lot in this country, that at the top of the market, on the la-de-dah ritzy banks of the rivers Test and Itchen, the anglers path is carefully mown to a refined 2" cushion of lustrous green, with stripes that make Lords cricket ground appear positively rural. Down market a bit, even the most adventurous of British chub stalkers can usually head-butt and elbow his way to within casting distance of the fish.

In the absence of real jungle warfare, a modest pocket-knife is generally all that's required. A small, sharp knife can perform countless functions for the angler. I use mine for cutting fish bait when piking, cubing meat for barbel, cutting up discarded line, and I once even whittled myself a rod-rest, when I was improvident enough to leave the proper ones at home. There again, if the pocket-knife is one of the multi-talented Swiss Army types, then all sorts of facilities are immediately to hand.

Until earlier this year I had two pocket-knives that lived either in my fishing jacket, or my tackle bag. The first I managed to obtain some years ago, very cheaply indeed: I confiscated it from my (then) eight year-old son. Even with my notoriously liberal attitude to such things, I thought he was a rather too immature to become a dashing young blade. That knife, an Opinel No. 8, is a very basic, but nonetheless excellent tool. When a family of Frenchies disgorges from their Renault Espace for le picnic at an autoroute service area; bread, cheese, and apples are often on the menu. Papa Frenchie will pare away at each with his pocket-knife, transferring each morsel from the blade to his mouth, miraculously failing to cut out his tongue as he simultaneously scoffs and holds a six-way conversation with les énfants. The chances are that his knife will be a battle-scarred Opinel. The French company that makes them has produced tens of millions of the things.

The Opi has just a single blade that relies on a loving owner to keep it from rusting - it's not stainless, but it does have a most pleasing shape, and a curious turn-collar means of locking the blade safely open. Having played around with knives a bit over the years I have to say, I've never found a blade that sharpens as beautifully as the cheapo Opi.

If you're in the market for a basic pocket-knife at an affordable price, the Opinel would be my first suggestion. The smallest size fits into a matchbox: the biggest is beast enough to raise a grunt of approval from Crocodile Dundee. Oh! and the other useful thing Opinel make is a little folding saw. I'm not suggesting that we should all go around cutting swims as we go, but a little saw like this can often do a good turn at the beginning of the season, when the spring growth flourish has obscured your favourite swim.

My second knife was one of the multi-fingered Swiss Army types. I say was, because after an innings of nearly twenty years, I dropped it into thirty feet of brown water at the Vaal Dam in South Africa, earlier this year. That knife had blades, scissors, screwdrivers, a magnifying-glass, a full size lavatory, and goodness knows what-all else. I was very upset to loose it so stupidly.

If funds permit, that sort of knife has much to recommend it. Twenty years with that dearly-departed Swiss special proved that most of the gadgets will come in useful only rarely; but when you really need a Phillips screwdriver to tighten a reel screw, or a pair of tweezers to remove a thorn from under your finger-nail, it's nice to know that they are to hand.

That old friend, which had been made by Victrinox, just had to be replaced, and I looked really hard at all the options. I eventually plumped for a similar version made by the highly respected Swiss firm of Wenger, (pronounced Venga). The new knife has everything that the old one had, plus other useful bits like two-stage pliers, a saw, and a built-in kitchen sink, (I'm only kidding about the sink) and has quality enough to last a life-time. If you're buying a Swiss Army knife it's essential to make sure you're getting the real thing. There are an awful lot of cheap copies on sale, and I know from bitter experience, that they just don't last. You can't go wrong with a Wenger. The all singing and dancing ones are a bit bulky for a pocket, so a belt pouch is a worthwhile extra.

The big news in all-purpose knives is the Leatherman folding do-it-all type. Leatherman were the original, and they have been much copied. Top of the range is the amazing Wave model, and even the tiny Micro has about ten different tools incorporated into it. This is the ideal thing for attaching to an extendable 'zinger' on a fly fisherman's accessories vest.

For those who eat what they catch, even occasional partakers like me, the other knife that will to be a very good investment, is a first class filleting knife. The difference that the right tool makes in the filleting operation is just amazing. Filleting knives often come with instructions on how to do the job to perfection, but it takes a degree of skill which comes with time. My American Buck Fillet Knife takes an edge so perfect, and so sharp, that with it I can shave the hairs off the back of my hand. That's a test I wouldn't recommend unless you have two steady hands. When actually using a knife of this sharpness it really does make sense to use a protective glove on the hand holding the fish, (usually the left hand): ideally, one of the special woven stainless-steel jobs made by Normark. They are cheap to buy, and could save your wife from collecting the insurance benefit too soon. The fillet knife is not the sort of pencil-sharpener you'd like the police to find in your pocket should they have reason to search you, so it's a tool that should stay at home, well out of the reach of the kids.

If you do decide to invest in a good knife it makes good sense to keep it in tip-top condition. Any chef will tell you that the most dangerous knife in the kitchen is the blunt one. The Yanks have the blade honing business off to a fine art, but very few Brits seem to understand the process.

There are two distinct operations in putting a really superb cutting edge on a blade. The first is the shaping of the edge. You'll need an oil-stone, or water-stone: the sort that carpenters use for their planes and chisels. I try to hold the blade at about 25ˇ to the stone. I've found that the secret is to pretend that I'm trying to carve a thin slice off the surface of the stone, whilst pushing the cutting edge smoothly away from my body. When one side is partly honed you swap to the other side of the stone and repeat the operation with the other hand, or alternatively, if you are very one-handed, you turn the blade over and repeat (carefully) with a towards the body action. The art is in maintaining a consistent angle of attack on each side, and throughout the carving action. The Americans have some excellent honing guides which make the whole thing very much easier. The best I've seen are made by a company called Gatco. I've also heard tell of diamond hones that fit the same system, which produce the finest of finishes. I haven't come across them in England yet, but they're on my shopping list.

New knives seldom keep their sharpness for long, so they need some work to bring them to a lasting edge. Most good oil-stones have a medium grit side, and a fine grit side. Once the basic shape is achieved with the medium side, it's time to turn over to polish the edge to perfection. In truth, perfection is hardly the word, because no matter how perfect you may think the edge is, a quick look under a microscope will reveal that your meticulous ministrations have actually produced a fine saw-edge. The art is in making that saw-edge as fine and as consistent as possible.

The second operation is the aligning of the newly-sharpened edge. It may sound daft, but believe it or not, the thin metal left after the honing process is actually bent one way, then the other, by the pressure of the blade on the stone. The object of aligning is to straighten the cutting edge. The classic way to do this is with a proper butcher's steel - gently stroking the edge first one way then the other. Butchers do this with their huge carving knives, but you've got to be pretty nifty to do it with a pocket knife. I've got a handy little gadget called a CS24 Ceramic Sharpener made by Whitby: a sort of criss cross of ceramic sticks which do both sides of the blade at once. It's small enough to carry in your pocket for use at the waterside. You'll often see your local butcher stop cutting, and give his knife a couple of strokes on the steel to re-align the edge, and it's a habit that's worth copying.

High quality stainless blades need the whole treatment: softer steel, (like the Opinel) can be brought to a razor-like edge with one of the multi-disc kitchen knife sharpeners, which sharpen and align in one easy operation - mine is made by Prestige. There's no doubt that the use one of these is cheating, but it saves a lot of time and effort.

Across the Atlantic there are knife museums, specialist knife shops, and an annual trade in knives that runs to many millions of dollars. Companies like Buck, Shrade, Remington, and Browning, each produce a whole range of superb blades for every purpose. Frankly, I think they've gone over the top about the whole business.

We anglers in Britain are unlikely to reach the American level of preoccupation with knives, and I'm not suggesting that anything of the like is either necessary or desirable. Nevertheless, a good quality pocket-knife is a pleasurable sort of thing that will also give service through many years if serviced properly. You may also find, like many an American grand-pappy, that bye n'bye it becomes a trusted and valued friend.