A scuba diver will next weekend attempt to break a Guinness World Record by spending 40 hours underwater in aid of the Aquatic Environment Protection Charity he recently set up.

The world record for salt open-water dives stands at 24 hours and 35-year-old Irishman Sean McGahern, who only started diving six years ago, is gearing up for the challenge, determined to break it.

His training so far has seen him stay underwater for 12 hours, trying and testing his equipment, gas mixes, decompression times, nitrogen and central nervous system levels, anything that goes into keeping a human being alive in a fish’s environment for close to two days.

The event will be held at the Reef Club at the Westin Dragonara Resort in an underwater valley that is always sheltered. Only a force five wind and more would be a cause for postponement.

Mr McGahern is “quite confident” he can survive the 40 hours underwater, starting on Saturday at 3 a.m. to surface at 9 p.m. on Sunday. “No one has ever tried to do something like this here,” he said.

He has clocked up about 700 dives since he took up the sport as a mere hobby before deciding to take things seriously four years ago, becoming an instructor in two.

Mr McGahern is not put off by the fact that an attempt to break the record last December failed due to computer glitches and he will have no fewer than four top-of-the-range computers strapped to his arms, each costing about €1,400, just in case one shuts down.

Mr McGahern is not short of plan Bs and will even have a laminated sheet with pre-planned dive details in the eventuality that even the land-based computer monitoring his moves goes haywire.

The worst-case scenario is that he goes back to basics – to the way things were done before technology took over.

Neither is he put off by the fact that someone is already planning to break his record next month. “I plan to do the same next year,” is his comeback… and the competition goes on.

Working as security man at a bar, Mr McGahern knows a thing or two about safety measures and no stone has been left unturned. He will be wearing a dry suit designed for this purpose, complete with electric transmitters and battery packs to warm him up inside.

At a depth of 15 metres – and definitely not higher than 11 as Guinness stipulates – for almost two days, Mr McGahern is actually likely to feel warm. In fact, his dry suit, hanging after a 12-hour trial, may be wet on the inside… but from sweat!

It has been fitted with a latex sock around his neck to seal the opening and ensure water does not seep through. One of his trials, in fact, had to be cancelled when the neck opening started to move and he was up to his ankles in water.

Mr McGahern will also be wearing a full-face mask, which means he need not have to keep a regulator in his mouth as this could easily fall out due to muscle fatigue. But if that contraption were to fail, he has quick-release toggles to remove it, another two regulators strapped to his neck and a normal mask on stand-by at his waist.

Only a limited area on his neck is being constantly exposed to the salt water, which can have a “pickled” effect on the skin and lead to brittleness and erosion. But water-resistant, salt-barrier creams seemed to be doing the trick, he said.

It could get lonely, boring and dark down there and Mr McGahern has made provisions for this eventuality. He plans to keep active, engaging in a clean-up of the sea bed and offering specialised courses in underwater navigation, mapping, buoyancy and photography.

Neither will he be deprived of food but he will have to be satisfied with a diet of sugary juices, sugared water and soups he can sip out of energy-drink bottles as well as cream cheese and pâté from tubes. What he does with the food once it has been digested is another story…

Mr McGahern will also be regularly changing his twin-set tanks as no air breaks are allowed.

And when it’s time to sleep… well, even that can be arranged it seems. During his last trial, he did manage to catch 40 winks in his water bed.

He will also be constantly backed up by three divers and in the company of organised night dives. And the support will be spilling on to the shores, with friends travelling from overseas to back him in his aim to raise funds for the installation and improvement of facilities, such as toilets, at dive sites.

The plan is also to tie marker buoys with wire as their ropes are often cut by fishermen, the buoys removed and nets cast to catch fish in these areas, Mr McGahern lamented.

Donations for the cause can be made to the Maritime Environment account number 4001843991-1.