Go fly fishing and land a bagful just a cast from the smog and cement of the city. Words: TREVOR PADDENBURG

Be warned: you’ll get more than a few strange looks catching the tube home with a four-pound rainbow trout in a plastic bag.

“Got a fresh one from the fish monger, have you lad?” asks one bloke.

“Nah mate, been fly fishing in the countryside. Absolute ripper of a day,” I reply.

As bizarre as it is carting your catch of the day around London, organising a fishing trip from the capital is as easy as fish pie. An hour south-west by train from Waterloo and you’re in scenic Farnham, in the county of Surrey – home to rolling green countryside, forests full of squirrels and lakes stocked with trout.

Within minutes of stepping onto the platform you’ll be cruising the back roads with Go Fly Fishing UK guide David Martin, a man who talks about fish like most blokes talk about beautiful women. He loves the thrill of the chase and he loves hooking one even more.

“I’ve caught thousands of trout in my life but I can’t wait to catch the next one,” he enthuses. “The fresh air, the countryside, catching fish – it’s relaxing and exhilarating all at once.”

He’s not wrong. Later, when I hook my first ever trout, it’s a real rush, followed by an exciting tussle to get the four-pound fish to the riverbank.

It’s essential to use a very light line when fly fishing, so the fish is not put off taking the fly. But that means you can’t simply haul a trout in when it takes the bait. The adrenaline flows for the next five minutes as the silver- and rainbow-striped trout gives ground, then darts off again into the depths, with line zinging off the reel.

A fly fishing day trip is not all hauling in fish by the dozen, though. For fellow amateurs, the experience starts with a casting lesson in the park.

There’s no sinker or bait to use to create momentum, so casting a fly fishing rod is all about using the weight of the plastic-coated line. “You won’t catch nothing there,” yells one passing motorist-cum-comedian as we stand casting in the open field.

It’s a tricky business at first but after 30 minutes I’m casting a good 8-10 metres, though with none of Dave’s grace.

“Right. Let’s do the real thing,” says Dave, and we head off to Frensham Trout Fishery. The series of six lakes is set in an amazingly picturesque and tranquil valley on a property owned by grizzled fishing veteran Richard Twite, who loves hooking a trout almost as much as Dave.

In the next few hours, we pull in a handfull of the strong fighting fish ranging from 2-4 pounds. It’s good fun, and a relaxing, wholesome change from London’s bustle and boozing.

It’s not just for the blokes either. “The girls really enjoy it too cause there’s no smelly bait and casting is not about strength,” says Dave.

There are more famous fly fishing rivers in England like the Test and Chalk Stream rivers, but landowners demand up to £200 a day to fish. Far more reasonable and just as much fun is a trip to Farnham. Just be ready for some sideways glances on the tube as you head home for a fresh fish dinner.

• Go Fly Fishing UK do full-day lessons and guided tours (including gear) for groups of up to four for £157. Frensham Trout Fishery prices range from £20 (half day) to £40 (full day, keeping up to five fish) per person, with fishing gear for hire