I'M SURE most anglers do not remember the first fish they ever caught. Was it a salmon parr in a burn or a tiny pugnacious perch in a local loch or a little flounder at the mouth of some burn as it met the sea? But I am sure most of us do remember the first really big fish we ever hooked. Mine was a cod, and I vividly remember being amazed at its power as it hit my lure.

I was fishing from a small, and, I'm sure, not very safe boat which we had manhandled to the water's edge near the Cloch Lighthouse. Our subsequent choppy progress across the Firth of Clyde stopped short of Dunoon, over, or at least, we hoped in, the general direction of a spot above a shipwreck near rocks known as The Gantocks. No personal navigation aids in those days. The GPS and its like was but a glint in the eye of United State Military Intelligence . . . (I've always thought the words ''Military Intelligence'' were one of the prime examples of oxymoron, a bit like ''reasonable legal fees'' and ''happily married man'', but there we are) . . . and finding the right spot was often a case of lining up a church spire with a tree over there and an electricity pylon with a red phone box over here. One wag had suggested that once we found the right spot, we should mark it with a cross on the

bottom of the boat, but as any fool knows, it won't work. You might not get the same boat next time.

Anyway, there we were in the general direction of that famous cod mark off the Gantocks. The area had been brought to the attention of keen sea anglers by a motley group of Edinburgh chaps known as ''The Trio'' - Dougie Dinnie, Bill Freshwater (a wonderful surname for a keen sea angler), and George Mann. They had discovered that there were runs of large cod to be caught off this mark and had also pioneered what to us was a new method of fishing called ''Pirking''. Basically this consisted of fishing a large, silvery, fish-shaped lure at the end of the line, letting it drop to the bottom and then fishing it lift-and-drop style.

It sounds simple, but the actual rhythm of the lift and drop turned out to be crucial and it was fascinating to see how two anglers fishing with the same kind of lure and only feet apart would have a markedly different success rate dependent on their individual pirking technique.

Over the years the trio fished the area, they had more cod over 30 pounds than any other group of rod fishermen in Europe and being a genial bunch, they were always keen to help the less experienced anglers. There was an excellent film made of their exploits at the time, called ''Run of the Wild Fish'' and it is an informative and somewhat poignant reminder of a time when fishing in the Firth of Clyde was good and we all thought it would remain that way.

So, down went the pirk and hit the bottom. I clicked the reel into gear and lifted with the jerky movement that I had been told would work. I thought the method should be called ''Jirking'', not pirking, as this seemed to sum it up succinctly. The water was not so deep that you couldn't feel the resistance of the water make the lure wobble on the way up and as you gave slack line, it was easy to imagine the lure sliding and flashing its way back down to the bottom. As you lifted and the line tightened again, the lure was obviously acting like a small fish in distress and sending out just the right signals to a hungry cod.

I had not been fishing long when I got the lure stuck on the bottom. It was fairly rough down there and I'm sure there were enough lures attached to the rocks to open a sub-marine tackle shop. In these circumstances there is usually nothing for it but to try to break the line. The drifting boat helps and generally either the line breaks or you are lucky and the pirk come up none the worse. This time neither happened. As I strained to release the pirk, I was aware of a powerful force trying to take it the other way.

I was into a really large cod for the first time and, having tightened the clutch to free the bait from the bottom, this fish was now bending the rod to the limit. The line was singing in the rings and I knew that if this was what catching big fish was like, then I wanted more of it.

Slowly I pumped the fish towards the surface until a huge, creamy-green shadow appeared. It was estimated that I was into a 30 pounder at least. But I will never know. The hook hold gave, the fish flicked its tail and slid slowly back into the depths.

I have never forgotten the power of that first really big cod and though it is unlikely that I will ever hook as big a fish again, I thank the Firth of Clyde for the memory.