I used to have a bit of a thing for the Usk. I was active on a chalkstream in Dorset at the time and was perfectly happy but needed a change now and then.

What a river the Usk was in spring. The best way to blow off the shack nasties of a too-long British winter. The Usk in spring was mercurial: withdrawn and inaccessible one moment, all over you the next. And though the trout were always hard won, we never blanked. (Read early trout – how to be successful at the start of the season.)

The Usk – fantastic in spring

The beat was mine for the day, so I felt in even less of a hurry, knowing that the river would be “coming on” just as I got to it. It was a bright, buzzing spring day. Only a few vaporous white sheep grazed across the open blue sky, dragging their shadows across the fields and hills beneath them. The April sun pushed a little warmth into the air as I strolled from the shadow of the wooded valley-side out across the meadow that slopes down to the edge of the river.

The day was perfect.

Large dark olives and March browns hatch in waves in April – pulses. The river can be dead one minute and boiling the next. When the boil happens it will last between 10 and 20 minutes and then all will go quiet again for another half-hour, though the odd fish may still splash about here and there. It’s fishy surfing. You have to be ready or you’ll miss the wave. And yet there will only be between six and 10 waves, even on a good day. If you catch one fish out of each you’re doing well. So there are tricks to be learnt and one of the best on a beat as intensely packed as this one is a memory game.

The hatch comes on and fish start rising all over the river. You’re in one spot so you stick to it. Move around too much and you’ll miss line-on-the-water time. But what you do is make a mental note of where all the bigger fish are moving, even the ones beyond range on this particular hatching wave. When the wave has run out on the reef and the river goes quiet again, that’s when you move into a good spot for the fish you marked earlier. (Read: The top 10 trout rivers)

Another trick, more or less related to the last, is not to give up hope when all is lifeless. It is very easy to imagine that a river is empty in April and to pace up and down it restlessly. But everyone who knows rivers like the Usk well will describe how the rise comes on “as if someone had flicked a switch”. And it really is that sudden. A dead flow will transform into boiling soup in seconds.

Blink and the wave is gone

As it did about 10 minutes after I arrived. I caught a couple of trout out of that wave – noticing a belter beyond drag-free reach on the far side of the same run – each of these just under a pound and fit as butcher’s dogs. And a couple on the next, one of which was well over a pound. Usk fish are so mental that a pounder like this that gets downstream will feel like a runaway medicine ball.

Olives came in balletic drifts downstream, in flotillas, their wings vibrating in the spring breeze until they had dried when each fly flicked away suddenly into the air. And the trout were hitting accordingly in urgent, splashy rises. It was a day of trout fishing bliss on one of the best trout rivers in the country, a heavenly reprieve from the dark days of winter.

And time ticked on. At one I ran up the hill and breathlessly, still in waders, walked in on the gathering of local press and fishery owners here to launch the National Park’s Fishing Guidebook and its detailed listings of all the beats now available on the Usk that were never accessible in her more parsimonious Nineties. The Wye and Usk passport scheme has made this once sequestered river busy, with beats up and down and amounting to miles of water – fabulous bits of water like Glanusk and Fenni Fach – now accessible by day ticket. I’ve occasionally wondered whether the public fishing of open spaces like Montana or New Zealand wasn’t something to be envied, and come down in the end on the side of how we’re just too crowded an island for that ever to work here.

But on the Wye and Usk they may just have found the perfect compromise: it is genuinely a trout fishing river to compare with the Big Hole or Gowan.

Trout fishing on the Usk

• Tackle and flies: best take a 9ft 5-weight with a floating line. Optimum flies are dry March Browns for the March browns, Adams size 14 and 16 for the large dark and medium olives and size 16 CDC or Elk Hair Caddis for the grannom. The Usk boulders are slippery, so use waders with felt soles and a wading staff.
• To arrange your trout fishing on the River Usk visit the Wye and Usk Foundation and follow the link to fishing where you will find all the information you need.
• To order a National Parks Guidebook email enquiries@breconbeacons.org or go to any tourist information centre in the National Park.

This feature was originally published in 2010 and has been updated.