Johnny Watterson talks to the 24-year-old endurance swimmer as he prepares for the late August day when he will attempt to swim the Irish Sea

One town. One Jim Swift. In Tramore there could be only one Jim Swift. Jim is the fella from up on the the hill overlooking the villas and cottages and chalets of the seaside resort, the local lad, who once swam the English Channel. Big Jim. You can see him out in the water when the summer warms the bay. Sometimes for two hours, sometimes four. Sometimes he'd be getting in the water when the first bathers arrived on the strand and he'd be there when they were packing off home, pulling himself across from the two towers at the point in Brownstown to the small cove beneath the cliff at the Guillamene two-and-a-half hours away.

One life. One infatuation. In Tramore, Jim Swift is the swimmer you can see most days up past the big wheel and the dodgems, past the coffee houses, pizza parlours and gaming halls at the end of the promenade in Splash World. Jim, with his unkempt black beard and alert eyes, is the young trouper who this week arrived before the doors had opened and then swam non-stop for eight hours and one minute. Up and down the 25-metre pool; kids splashed, screeched, larked around him during his 1,000 lengths, his 25-kilometre session.

In Tramore there could only be one Jim Swift, Jim the student, who plans to swim the 35 miles across the Irish Sea to England.

As a boy, Swift entertained the notion that he might well be misaligned with the rest of the town, endearingly out of kilter. His befuddled young mind couldn't work out why he and some friends would kick off the bedclothes on hostile January mornings before 7am and pilot their mountain bikes, through wind and razor hail, out to the Guillamene for the love of plunging into freezing water. Nonsense days. Teenage boys with ideas.

"Your hands would be stuck to handle bars. It could be hailstoning. Freezing. And you'd just get in," he says. "I mean, there was no plausible explanation for it. I always thought of myself as a misfit. I thought I was the first to come up with this.

"Then one day I got a surprise watching the news. There was this grown man talking about swimming across the English Channel and how it was a benchmark for open-water swimmers. Suddenly what I was doing got this seal of approval. The thought never crossed my mind that it was a sport. I just thought this was some pastime Jim had come up with.

"All of a sudden, I had an arena, a goal where I could test my capabilities. Any hurler knows that if he's good enough he has Croke Park as an arena. When I heard of the English Channel, I realised something like Croke Park existed out there.

"I remember saying out loud that day 'I'm going to do that'. Ten years later I did."

Swift says that after a long swim his body is not in mint condition. After the Channel swim his shoulders felt as though someone has plunged a dagger into each one. So numbed with cold, his hands and feet didn't belong to him. He couldn't feel the water or land. In a long swim nothing is spared. Swift says the monotony is crippling. If you are not able to get your brain to somehow entertain itself, you'll find yourself replaying the chorus or a line of a pop song you just heard on the radio before you got into the water.

He says when it gets bad he finds himself singing Reach for the Stars thousands of times over a six-hour swim. He says it's the worst kind of hardship you can imagine. But in the pool it's worse.

"Every time you hit the wall it disturbs your rhythm. It's like hitting the CD player and it skips. There's not a flow," he says. "That swimming pool there," he continues, pointing out to Tramore Bay, "is two-and- a-half miles wide. There's much more rhythm. You can kind of have a conversation with the water as you're pulling and stroking along."

His first swim, a classic, the Channel, began with violent vomiting. That tore the lining of his stomach. He had hoped for 10 hours, but hit France four hours later than that. He was 20 years old and felt successful and high, but beaten up. The sea had consumed his body at the rate of 14 pounds in 14 hours.

"It's very traumatic for the body and it will take a few months to recover fully," he says lightly. "Even long-term, my shoulders are beginning to wear out a little, my elbows have really started to complain. My hip is screwed, my knee is f***ed and I'm 24. I'm not biomechanically blessed. From my history of playing rugby, GAA and hurling, only some of which I was completely abysmal at, I picked up a few injuries and now I'm working on some more."

One obsession had been satisfied with the Channel swim, but even before the first eruption of citrus energy drink, seawater and blood, another fancy had been squatting in his head. On the trip over from Ireland to England, the student and his father, Declan, had been talking as their boat cut through a beautifully calm and tranquil sea.

"Wouldn't it be great to swim this?" said his dad.

Today it is summer in Tramore. People have come outside just to look, improve their waxy pallor, take comfort from the promise of long, bright days. The pool in all of its suffocating heat and sterility and chemical mix has served its purpose over the winter, but the ocean is why Jim swims. Soon it will be warm enough to train there.

He never really thought long and hard about attempting to become the first person to swim to England, to immerse himself in the Irish Sea. His father's remark simply stuck in his head and, after a year in San Francisco, the lightly-offered idea had evolved into an imperative.

"I became too satisfied for a short while that I'd achieved something," he says. "On reflection, I hadn't.

"When I started to look and see if the Irish Sea swim was possible, I decided it was. It's not a fantastically long distance. It's 50 miles that will end up as 60. It's definitely within the realms of human endurance.

"The Channel swim was obviously difficult. But I think people break mentally before they do physically.

"People have asked me, did I ever think of quitting, and my answer has always been 'I didn't'. The one thing I'm sure I do possess is some sort of mental fortitude. I didn't think of ever quitting and I don't think I will on this one. If I'm physically half able I'll be mentally able. It's about preparing yourself for the conditions. I swim in the pool and splash out five hours a day as often as I can, but as soon as the sea is halfway warm, I'll get in and swim for five hours there.

"I'll make sure I'm really, really hungry before I get in the water. When you swim for 35 hours, you can't take on solid food. You're only able to take on liquid food. The first six hours are usually not a problem.

"Then you begin to get really hungry. After another 30 hours, your stomach feels like it is going to implode. You can feel yourself actually getting physically lighter. All the fat cells in your body . . . you consume them as a source of energy. This time I'll probably lose more than a stone-and-a-half. There are other issues.

"When I train, I always train with nettle stings to simulate jellyfish stings. Yeah, it's painful, but you do get used to it. There are no jellyfish stings that are so painful that they make you stop.

"The thing that happens is that the accumulation of all the misery you are going through will put some chinks in your mental armour, and then you begin to entertain the idea of giving up, like you've done enough to be proud of yourself.

"So a jellyfish sting will not make you stop, but a jellyfish sting coupled with the extreme hunger, coupled with the mild hypothermia you are suffering, coupled with the litres of lactic acid in your body and the exhaustion and the cramps and the seasickness and your goggles cutting into your eyes - that's what makes you stop."

Too pragmatic to romanticise the sea, when Swift talks of the swim you understand there is an infatuation at work. The swim is an exploration of the relationship as much as a savage test of his endurance. Occasionally on his training journeys, dolphins and seals join him, their brief companionship for precious moments softening the hardship. Alone in the water, they make him feel as though they are all one community sharing the same living organism, the ocean. He feels like a visitor there, and when the dolphins arrive it's a welcoming. He's at home. Open water is different to the pool. It's animated. It's dynamic. He likes the coldness. He likes the taste of the salt. But 35 hours immersed in it, he knows, is an act of vandalism to his body.

"It's more important to be mentally strong than physically strong," he says. "There's a lot of time for self-reflection in the sea. All the time you're asking yourself: 'Am I good enough, can I keep going?' In my head there are two sides. One side is encouraging, the other side abusive. It says 'Ah look at you, you can't keep going.'

"I'm in the middle going 'Ah lads, won't you shut the f*** up, I'm trying to do a swim here'. If the side of your brain that says 'Give up! You're s***' begins to win out, then it's hard to hold out. There's nothing there to preoccupy you. You look up and see blue sky. You look down and see a dark blue abyss."

One hat, one pair of goggles, one pair of togs is all he is allowed. His trail boat will never stray more than 10 feet. His older brother Larry, younger brother Brian and his father will be there, and also a doctor and a navigator, to plot the wind, currents and tides, which will change six times.

Late August he will push off from near Carnsore Point and aim for White Sands Bay in Pembrokeshire, Wales, but not before a simulation. In four weeks he will stay up all night and won't eat for 24 hours.

Then he'll wade into Tramore Bay and stroke for 10 hours. Much more mileage than that and he wouldn't recover in time for the real swim.

"I'll be extremely hungry. I'll have low energy," he says. "I'll be deprived of sleep and I'll swim into every jellyfish I come across just so I can simulate the worst possible conditions. Hopefully, it will prepare me for what I have to go through."

For the Channel swim he started at 8.45pm and swam off into the night. He took to the experience. In the dark, the wind drops off, the sea is calmer. It's soothing and comfortable, he says, if you don't allow yourself "to be freaked out" by sharks or jellyfish or oil tankers.

One life. One Jim Swift. At the extremities, where much of the swim takes place, the planning, the training, being a "social leper" and even the certain brutality of the experience, all make sense. A lifestyle of "PlayStation and eating burgers" has ephemeral attractions but little else, and he knows, even at just 24, that 46 years from now at 70 years of age he will remember the standout days, the 14 hours, the 35 hours. His times in the sea are future comforts.

The necessities of what he does have also taught him to draw from thin resources. Ten miles from land and locked into his bleak world of physical suffering, that sometimes pays off.

"Swimming in the dark . . .," he muses, "sometimes, just sometimes, you can make out the white air bubbles coming off your hand each time you stroke."