Beth Robertson Fiddes on how awards and an adventurous streak have affected her art

“I had the idea that I was going to do something like the paintings he did. I was going to do something really big and use lots and lots of squishy paint. I gave the picture to the dog, who was thoroughly unimpressed with my efforts.”

Some 35 years later, Robertson Fiddes found herself painting again on exactly the same spot. The picture, Tiree Wave, is one of the highlights of her first solo exhibition in Edinburgh’s Doubtfire Gallery, a beautiful large-scale study of the moment a big wave crests. “It’s a special piece,” she says, looking into the depths of the blue-green water. “It was what I meant to do the first time.”

Robertson Fiddes, 39, has had “a brilliant year” since winning second prize in the Jolomo Bank of Scotland Awards for Scottish landscape painting last June. The £6,000 prize has enabled her to go on painting trips to Harris, Assynt, Mull and, this summer, to fulfil a lifetime ambition to visit St Kilda.

“It’s just had such a huge effect, it has freed me up to be able to make the trips, to think and do the work without other concerns. I’ve been able to make the journeys without having to worry about whether I would sell enough to keep the studio going. And I’ve had a lot more interest in my work because of the prize, which has been brilliant.”

There’s no need to ask about the kind of landscapes that fascinate her: the gallery walls are filled with paintings of rocks and water, the texture and colour built up with layers of paint and collage. She is drawn to isolated places which have an air of the primal and mysterious, even if she has to hike for ten miles with a tent on her back to reach her chosen spot. In the name of art, she has scrambled over jagged rocks, balanced on cliff edges, and encountered seals and sea otters while sketching in the teeth of Atlantic waves.

“I like to get to places that are not really on the track. You can do that when you’ve got a lightweight tent. When I went to the west side of Rum, I wild-camped for a week, catching fish in the loch, and spent the whole time drawing rocks. I also hiked six miles carrying all the water I thought I would need – though I then realised there is quite a lot of water on Rum!”

There is a beach on Rum, she says, which “looks like someone has gone with a boatload of Henry Moores and tipped them out, and they’re just sitting there waiting to be discovered”. She enjoys landscapes like this – the rock formations in Happy Valley on Tiree is another – where the shapes are mysterious, somewhere between natural and man-made. “It goes back to being a child on Tiree and not really knowing where these things came from. Some of them have such an ominous quality. I’m exploring some of those ideas again in my work, a time when there seemed to be more possibilities in what things were. There’s quite a sense of freedom in that, it’s a different way of seeing things.”

When she returned to Tiree, her childhood sense of the landscape came flooding back. “Though the island does look like someone’s washed it since I was there last,” she laughs. “There are beautiful houses where there used to be just derelict barns. We had an outside toilet – our poor mother, with two kids under five – and that was perfectly normal at that time.”

From her early days on Tiree, she has never wanted to do anything but paint. “Everyone around me seemed to be painters, I just thought that’s what you did.” Since graduating from Edinburgh College of Art in the 1990s, she has juggled painting with family life and a part-time job in a fishing tackle shop. “Prior to the Jolomo Award, I would plan a trip months ahead. I knew I needed to get a certain amount of work done and if it rained it was a disaster. Now I just go, and look as much as I possibly can. I can let the work take its own course.”

Her voyages have taken her to the outer edges of Scotland, to the west side of Iona (“much wilder than the east side and completely unexpected”), to Fingal’s Cave on Staffa, (“You can really imagine some ancient people built it, it’s all on a very human scale”), and to the west of Harris, near the Sound of Scarp, “where the water always looks tropical, although in fact it’s absolutely freezing.”

For many years, however, she dreamed of visiting a place further out still, the islands of St Kilda, inhabited until 1930 when the last remaining residents were evacuated at their own request. The islands are now a World Heritage Site in the ownership of the National Trust for Scotland, home to dramatic scenery, rare wildlife – and a small military base.

This was the first surprise for Robertson Fiddes. “The radar range looks like some kind of 1970s Bond set. There are Land Rovers running up and down to the base, and the constant hum of a generator. It’s not what you see on wildlife films. It’s not a bad thing, it just made the whole experience quite surreal.” She headed at once for the far side of the main island, the back of the back of beyond. “St Kilda far exceeded all my expectations. The cliffs are just amazing.” The nesting seabirds, however, were less enthralled, and attacked her at every turn.

She marvels at how people lived on the islands, harvesting birds and bird eggs from the cliffs and “stacks”. “The prospect of people spending the winter out there is quite something. We saw where they would land on the stacks, and even in calm seas I can’t see how anybody would have got onto that rock and climbed up. I’ve got a head for heights, and even I was wobbly. You have to keep looking up to make sure the skuas aren’t going for your head, and then you’re looking down to make sure you’re not about to fall to your doom. I can’t imagine doing that with just a bit of rope.”

And St Kilda had another surprise in store: the mice. “St Kildan mice [a protected sub species] are bigger than normal mice and furrier, so they look a bit like hamsters. The first time I saw one, I was really careful not to disturb it, to get a photograph to say I’d seen one. Then it transpired that they were everywhere. They’re frightened of nothing, they were even trying to get into the frying pan when I was cooking.”

She hasn’t yet made any paintings of St Kilda – “a large part of producing my work is not just about going to the place but thinking about what it means” – but hopes to begin in the New Year. And, of course, one visit wasn’t enough. “It’s not that easy to get to, and we thought at one point we weren’t going to get away from it, it’s very weather-dependent. But I would have loved a bit more drawing time, so hopefully I’ll get back soon.”

• Beth Robertson Fiddes: Paintings of the Land, Paintings of the Sea, will be at the Doubtfire Gallery, 1-3 South East Circus Place, Edinburgh, until 4 November. The Jolomo Bank of Scotland Awards 2013 are now open for entries, the closing date is 14 January, 2013. For more information see www.jolomofoundation.org