A FORMER teacher who swapped his five times table for flippers will feature in a TV programme about life on the River Wye later this month.

Dewi Roberts, who spends his days beneath the Wye’s murky depths, will be shedding some light on those dark depths and bringing stories of the Sea Trout, Hydropsyche Caddisfly and the Catshark to the surface as part of ‘Land of the Wild: Secrets’, which is being shown on Wednesday, March 31.

Narrated by Michael Sheen, Thursday’s episode follows the real-life Aquaman as he reigns over his watery kingdom of Atlantis – otherwise known as the Wye.

“I’ve always loved rivers, I’ve always lived on or near the river, in Montgomeryshire, and the photography is just a passion that’s turned into something far more than that,” said Dewi, who is actually known throughout Mid Wales as the River Man.

“Rivers are a massive passion of mine and I’ve specialised in underwater photography for about 25 years. I’m doing something I love, where I love.

“Powys is such a beautiful place and I’ve seen some fantastic things here. I enjoy all aspects of it, the wildlife and the river itself. Everything I see underwater is special.”

Delving into the crevices of the Wye Valley, the series is an extraordinary journey using innovative camera technology to uncover the hidden worlds of Welsh wildlife. It is a story of survival and romance set against the backdrop of some of Wales’ most breath-taking landscapes; from the Red Grouse on the dramatic mountainous uplands, to the illusive Catshark and everything in between.

BBC crews worked with Dewi over a few days as the Llangadfan native filmed on a stretch of the Wye known as Gilfach, close to his Llanidloes home. Dewi’s camerawork helps Sheen to tell the story of a Caddisfly experiencing issues with a nuisance neighbour throwing away unwanted goods as he cleverly weaves a net of silk to try and catch food. Dewi, who quit teaching six years ago, goes on to explain his lifelong passion for the magical underwater habitat that the Wye has to offer, and how he has dedicated his career to capturing the wildlife inhabiting it.

“When you’re under water with your snorkelling gear, it actually opens your eyes more than you’d expect. You can see them better,” said 56-year-old Dewi.

“A day’s work is a combination of me being in the river in a wetsuit and other cameras set up. I’ll be out filming under water for six to nine hours every day, filming salmon or sea trout or dippers or otters, kingfishers. I’ve got a balcony here at home looking out on the river.

“Fish will get used to you. As soon as they realise you’re not a threat and you stay still, you’re fine. I’ve had a big eel, three feet long, come up to me once, which was a magical thing. They’re just coming up to me just to see what the hell I was doing.”

Dewi refers to himself as 'Dyn yr Afon' (The River Man) on his Twitter account, but the name was actually bestowed upon him by a friend.

“I was involved in writing a book on Dolanog and one of my co-authors called me the River Man. It stuck and everyone now knows me as the River Man,” he said.

Despite being at home on and in the river, and even at one with the water, that doesn’t mean Dewi is immune to the dangers it poses. He broke his leg a few years ago and was stranded for hours until being found – by a dog.

“It can be dangerous. I broke my leg while filming in the Vyrnwy about two years ago,” he added.

“Somehow my foot slipped, twisted underwater, and I snapped my tibia and fibula. I fell in the river and it was trying to carry me down. I had a hell of a job to get out. I was on a rocky bed and heard a crack so I knew I’d broken it. I tried to get up but I could feel the bones moving.

“I got out eventually but was shattered, it had taken me 20 minutes. And I just had to stay put and call for help. I knew I had no signal, I shouted and luckily a dog walker eventually came by.

“I was out there for two hours, soaking wet, in shock. The fire brigade came from Llanfyllin, the Air Ambulance too.

“It can be risky but I’d rather do that than stay at home and watch telly. It made my relationship with the river stronger. It’s a hazard of the job, but I feel completely safe in the river, I feel safer there than walking down the street.”

*Land of the Wild: Secrets, featuring Dewi Roberts and narrated by Michael Sheen, is showing on BBC One Wales on Wednesday (March 31) at 7.30pm.