It’s a long way to Akureyri, but even further to Lake Myvatn. To get there, you have to drive from Iceland’s bleak northern capital through what feels like an ancient landscape – volcanic and steaming – but is in fact only a little older than Jesus. I doubt you’ll want to go. If you’re like my colleagues, you find the idea of standing in water for hours trying, as one put it, “To pull a disgusting fish from its peace below the surface just to look at it”, inexplicable.

Add that Myvatn means “midge lake”; that the accommodation is reminiscent of the prefabricated blocks I lived in while working for a mining company, and that this all-inclusive holiday cost me a life-scouring £600 a day, and my guess is you’ll be going to the Blue Lagoon instead. I’m glad, lovely though I’m sure you are.

I find myself locked in an epic battle. I can tell from the way the fish fights that it is big

For it’s the point of fly fishing to find oneself in the arse end of nowhere. For my friend Robert, his 12-year-old son Angus and me, bumping along a track in guide Gísli Árnason’s SUV, past the closed-up home of a farmer who has died without heirs, this is the business. The Upper Laxa empties from the lake in a multitude of braids, the waters warmed by underground volcanic vents. It offers the best wild trout fishing in Europe, possibly the world.

We climb down the last stretch, carrying our 9ft fly rods, crossing a bridge in a breeze as fresh as the white water beneath us. The path weaves between dwarf birch (the most overused joke in Iceland: what do you do if you’re lost in an Icelandic forest? Stand up), marsh marigold, meadow buttercup and Angelica.

Casting call: enjoying the solitude of fishing in Iceland. Photograph: Gísli Árnason

The wild brown trout grow fat on the midge that thrive in the warmed water, up to 12lb, and because their chance of eating is so short before winter returns, they are voracious. The rivers are owned by the local farmers, who license the sport out, keeping angler numbers low. In late July, the sun rises at 3.45am and sets just before midnight, yet the temperature is only 6C. The house we passed carries the foreboding of terrible winters in its simplicity.

Gísli sets me off up the bank. It’s not warm enough for the trout to be taking flies off the river’s surface, so I am using a “nymph”, meant to imitate an insect as it hatches and rises from the mud. I fish it upstream, letting the line come back towards me, trying to make the fly follow the bubble trail in the water that shows the seam where food gathers, striking at any movement that is out of the ordinary.

It’s bad enough fishing with Robert, an angler of supernatural skill, but he seems to have passed on his ability to his boy. Gísli goes with Angus, a great guide thrilled to help a youngster entranced by his sport. The net effect is that I stand a good chance of being outfished by a 12-year-old – not that it’s a competition, of course.

What a whopper … Ruaridh Nicoll with his 6lb trout

The water is clear, so I am keeping low, hugging the bank. Once in a while, I disturb one of the myriad varieties of duck that also feed on the midge, and they take off full of complaint. The water flows swiftly, a gym to the fish, so when the line twitches and I strike, the trout takes off at speed, and it’s all I can do not to fall into the depths. That’s just the beginning of my problems. The fish heads for the main stream, diving to the bottom so the line picks up weed.

Nearly all the fights are overwhelming, with me worrying for rod and line, and I lose many fish. The ones I get to hand, I carefully detach from the barbless hook and free back into the stream. Hours pass in rain shower and sun, and miles pass underfoot. We’re all racking up the numbers, and Angus is keeping a count – annoyingly.

Each session, 8am to noon, then 4pm to 10pm following lunch and a siesta, sees us on another section of the river, all different. One afternoon I find myself locked in an epic battle out in the fast water. I can tell at once from the way the fish fights that it is big, and what follows seems to last forever, a fight that wrecks the nerves. At last I pull in the biggest wild brown trout I have ever caught, weighing in above 6lb, its glorious freckled body in my hands.

A river runs through it … Ruaridh Nicoll doing what he loves best. Photograph: Gisli Arnason

Returning late in the evening, filled with fresh air, the rough and ready lodge quickly feels right with its warmth, solid stews and camaraderie. There’s a geothermal hot tub out in the cold. Robert, Gísli and I sit with cold beers in the hot water, gossiping.

The conversation turns to the farm we saw earlier and Gísli says it will be sold by the government. Then, recalling an interesting fact, he adds: “That farmer, he died in this hot tub. He came up here for a bath in the winter and, well he was found in here.” Robert and I look at each other and begin getting out. Gísli realises his mistake and tries to reassure: “It was properly cleaned afterwards.”

Yes, I recognise I probably won’t be seeing you there. But I am trying to work out how to afford to go back.

Way to go

Ruaridh Nicoll booked with Aardvark McLeod. The season runs from 1 June to 30 August, with prices from £1,800pp (prime dry fly: late June to early August) for three days and nights, full service, full-board single accommodation, shared guiding. Gísli Árnason can be contacted for guiding at icelandtroutadventures.is. There are direct flights to Keflavík from the UK on Iceland Air, Wow Air, easyJet and BA