Striking a balance between enjoying a holiday with his young family and targeting marbles, Gerald Penkler experiences fly fishing in Slovenia at a different pace. Photos: Gerald and Suzanne Penkler.

Crack. I froze as the solid chunk of limestone in my left hand budged under the weight of the dad bod. Having circumnavigated most of the gorge pool, my luck had run out. The wading boots scrabbled about, refusing to stick onto the faint seams. A panicked glance towards the water a few metres below. Blue, clear, deep. Cold. There was but one way out. Jump.

Splashing and sloshing onto shore, I chuckled. Ah, the enjoyment of adrenalin and adventure. It was one of our last days in Slovenia, and a solo fly fishing day for me. A chance to get out of the slow, relaxed lane of the previous weeks. A rough and tough fishing mission.

Two weeks prior we had headed into the unknown. Instagram makes Slovenia look like a fly fishing fairyland. It’s not only the mystical marble trout finning in crystal clear rivers. It is also the forested mountains, tall mountain peaks and glaciers in the distance. There is fairly good information about Slovenia, things to do and about the fishing. The real unknown for us was how we would manage exploring and fishing in this fairyland with a three-month-old baby and a three-year-old toddler in tow. The first hurdle was a 1 200km drive from the Netherlands.

“Keep your eyes on the road!” Winding along a mountain pass in Italy my focus strayed at the first glimpse of water.  Water so clear that you cannot quite estimate the depth, where fish appear to float, and stealth is critical. An hour later, after crossing the Slovenian border, stopping on a bridge we got our first sight of the Soča River. The blue water snaked up the valley of forests and mountains. The Soča needs no introduction as one of the crown jewels of Slovenia. However, there are scores of other rivers and tributaries too.

From the Soča bridge viewpoint, I spotted one trout feeding hard in the middle of the river. As my eyes adjusted, another pale shadow took shape, and then another. Before long I could clearly make out at least seven pale fish, all feeding on the sand. At the back of the pool, from under a rocky undercut, a huge head appeared. Fleetingly it paused, and then drifted back out of sight. I had no doubt. This was a marble. A big one. Tired from the long trip, but excited and energised, we hopped back into the car for the final leg of our journey.

The introduction of brown trout has had a devastating impact on the marble population. Not only do browns and marbles hybridise, but the hybrids also reproduce. So after browns were introduced it did not take long for pure marbles to exist in only a few isolated areas. The Fisheries Research Institute of Slovenia and the Tolmin Angling Club started a very successful programme of breeding and stocking genetically pure marble trout. Today, with continued management, the marble trout is no longer threatened, and the population continues to expand.

Marbles get big and grow fast. The historic record stands at a behemoth 55lb and 120cm. It is said that they could attain 150cm. Today, fish of over 80cm are considered trophies. These big fish are not found sipping mayflies off the surface – they are masters of ambush that lurk in and around structure or boulders. Any unsuspecting grayling, trout or goby that gets too close is fair game. Streamers, up to massive 20cm pike flies, are used to target the bigger fish.

There are three big challenges to catching a real trophy. Firstly, you need to find them. They are few and far between in big rivers. Secondly, you need to get a fly down to them. These rivers are surprisingly fast and in deep runs getting and keeping a big streamer down in the zone is difficult. In these areas, either very fast sink tip or very heavily weighted flies are used. Lastly, marbles need to be in an eating mood and not sulking or digesting under a rock. Higher and less clear water in early season is a prime time, but conditions are unpredictable. Later in the season, heavy rain can be your friend. The increase in water level and a reduction in clarity also tends to get marbles more active. 

Despite the excitement of seeing those fish, we did not fish the next day. Instead, we settled in with some walks, which were perfect opportunities to scout the rivers and access points.

Driving back from a morning walk, the baby let out the warning shot ­– a hungry grunt. The timing couldn’t be better, as we were near an access point on the Soča. While he was topping up, I clambered down to a steep section of river – deep, fast, and interspersed with big boulders. Climbing through some undergrowth and onto a big boulder, I saw it. Sitting ahead in a reverse eddy and in the shade of an overhanging tree was a dark shape. A good marble. I watched it for a while as it patrolled a small area. The big boulder next to it looked like the perfect place to intercept it.

Read the rest of this story in The Mission Issue 43 below.