THOSE of you of a certain age might remember the notorious Public Information Film, Lonely Water, which was shown regularly on TV for several years during breaks in children's programming. Aimed to warn children of the dangers of careless or foolhardy behaviour in the vicinity of ponds, lakes, rivers and streams, it featured an eerie faceless black-robed and cowled figure and a memorably sinister voiceover by Donald Pleasence, whose echoing final words "I'll be back-back-back...." are often said to have terrified and traumatised an entire generation of British schoolchildren into never going near water again.

Thankfully as I tramp across the stunning landscape of Snowdonia alongside swimmer and artist Vivienne Rickman-Poole, I'm able to banish all those horrific childhood memories and instead concentrate on the glorious surroundings. It's a boiling hot June day without a cloud in the sky and there before us are the twin lakes of Llynnau Cwm Silyn shimmering in the heat haze with a colour more reminiscent of something you'd see in the Caribbean rather than North Wales.

"It was a friend who introduced me to these lakes and I haven't looked back since," says Vivienne, who has made it her business to explore and document the hundreds of lakes, pools and rivers which are dotted across Snowdonia. "There is so much to discover here. When I first came here it was all about the mountains and reaching the summit but at some point I looked down and spotted all the lakes and it made me want to explore them instead."

Vivienne now takes groups of fellow wild swimmers to these hidden gems, offering bespoke tours where people can experience for themselves the freedom and beguiling solitude of these lonely but beautiful bodies of water.

"For me what makes mountain lakes so special is getting there, lying back and looking up at the sky or the landscape - you can't get better than that," explains Vivienne. "It gives me a great clarity of thought. You can't take your mobile phone or car keys into the middle of a lake and all the things you're thinking about just get left behind."

With forthcoming fatherhood playing on my mind, the chance to take a deep breath and dive in certainly seems an attractive one, especially on such a sweltering afternoon, but as we get to the water's edge memories of Mr Pleasance come flooding back and I'm looking at those sharp rocks, slippery surfaces and lack of lifeguards with the eyes of one bought up in a world of health and safety and risk assessments.

"It's best to go at this time of year," says Vivienne, who adds some of the pools are as warm as baths but are covered with algae. "It's unusually hot at the moment but it's best to take it slowly, pop on a wetsuit or thermals and do what makes you happy."

I'm slightly envious as Vivienne slides into the water with ease, leaving me clambering ungainly as I gradually lower my bottom half in. She advises me to splash some water on my face and arms first before launching myself under but when I do there's a gasp as pampered body reacts to what you've just done to it. There's no denying it's freezing cold and instantly I fear for the future of my toes, not to mention my other extremities. The water is crystal clear and suddenly deepens, leaving you feeling like you're in the middle of the ocean but with no current. It's incredibly easy to swim and the temperature means you body actually welcomes the movement as you attune to the surroundings and realise it's just you, the water, the sky and the towering cliff face ahead of you.

"I started writing narratives about each of my journeys into the mountains," explains Vivienne, who documents each swim with an underwater camera. "It's turned into poetry and has become something that's really exciting for me. People are starting to like what I do which boosts your confidence."

Far away in the distance we spot some red and blue specks high up on the mountain which towers above us. They look tiny but incredibly we can hear them speak to each other as they slowly ascend the near vertical cliff. I remark it looks like we're having more fun.

"There has been a massive rise in the popularity of outdoor swimming in the last decade," agrees Vivienne. "It's a free activity of course but of course I have mixed emotions because I want the lakes all to myself! Equally there's a joy when someone like yourself gets extreme joy from what you're sharing. I want it all to myself but want to share it!"

Vivienne will be bringing her expertise to this year's Good Life Experience festival in Hawarden where she will lead outdoor swimming and creative sessions in the brand new Lake area at The Good Life.

"I'll be running hour long guided swims where we will swim for 20 minutes followed by a creative workshop," she adds. "I'm going to show them how swimming feeds my creativity and we'll be experimenting with words and drawing. I've always been a swimmer but when I moved up here from Bournemouth I became fanatical. It is an incredible area and so peaceful. It's not just the landscape that is beautiful either. I don't come from Wales but I've found the community here to be incredible and so welcoming."

After around 20 minutes, I finally and reluctantly give into the cold and head for the shoreline where it is so hot my towel is barely required. Basking on a rock, it's impossible not to feel a sense of calm with your body and mind feeling like they've been literally cleansed. I'll definitely be back-back-back....

For more information go to www.viviennerickmanpoole.co.uk