“The next swim, from a wooden landing stage of a boathouse on a little trout loch nestling in a purple bowl of hills, was a sheer delight. This loch had a shallow end, where the burn flowed in, and a deep end where it was dammed by a stone wall and flowed down a salmon ladder into the sea.”

The briefest of breaks in the horizontal rain gives us our chance. Scrambling into our waterproofs, we grab our backpacks from the boot of the car and make a dash for the path, leading down from Jura’s sole main road (single track) and towards the top-end of Loch Tarbert.

There is no let up in the downpour. My broken wrist is protected by my kagoule and an old walking sock shoved awkwardly over the thumb. And still, as I stand with my back to the westward gale, the loch appearing in a sweep as I turn, I can understand completely why this place would be, is, the most enchanting place for a wild swim in Britain.

My five day jaunt here, with my dad, uncle and one of his close friends, was planned weeks ago, just before a tumble from my bike put paid to my late summer swimming plans. Yet here we are, following as closely as possible in Roger’s footsteps, if not swimming strokes.

We reach the small, padlocked boathouse and landing stage after a short kilometre walk in the foulest weather so far this autumn. Having pored over the OS Map during breakfast, we think this must be one of the key places where Roger swam during his walk across the island, gulping burn water in this small, cut off stretch at the very eastern end of Loch Tarbert.

While he got a drenching further north on Jura, we are taking a soaking on the middle of the island. Changeable barely covers the weather as we slip across the rocks and tramp over swathes of sea kelp. The sun briefly peeps out, for all of a minute, before another gale whips up the surface, white caps splashing over the bows of the small boats moored offshore.

A swim off the agenda, we set off down the coast to explore. With the weather closing in, the danger is this could turn into an unenjoyable tramp. Instead, I make my best efforts to look up, to imagine Roger working his way here from the western bay of Glenbatrick and then on, north, to his date with the whirlpool in the Gulf of Corryvreckan.

We come to what, in the distance, looks like a small burn working its way into the loch. In fact, it’s a foot deep stream moving at pace off the saturated, boggy mountains that glower to our west. Our only way across is via some exceptionally slippery stepping stones. And so we forge on, upstream.

As tributaries flow in, I go in search of a swimming spot and find one straight away. Sheltered from the wind and with the rain on hiatus, its surface is glassy, the colour of single malt. No more than three feet wide, its bed shelves gently, with a bank that could easily be negotiated in one step.

Just like when Roger looked out at the impossibility of Corryvreckan, my swimming shorts are folded neatly at the bottom of my rucksack, under a packed lunch and spare waterproofs. The weather, and my wrist encased in plaster, mean this is a swim that will just have to wait.

Instead, I dip my hand in. The water feels gorgeous. Soft and not at all chilly, I can imagine it would feel bracing before giving me that life changing hit of adrenaline.

Unable to partake, I stride back towards the boathouse, the weather worse than ever. I feel elated and can’t wait to return here with a wetsuit and both arms in working order. Roger’s lines about Jura resonate clearly. ‘To know the island as I do is only to realise how much more there will always be to discover of its beauties and difficulties.’