IT IS a world of shipwrecks, engineering marvels and movies, and returning from there can take longer than from the moon. But it is also a boom area for further education.
The deep sea is providing a wealth of career opportunities. The demand for commercial divers is increasing as the price of oil and the average age of North Sea divers are rising.
During the oil boom in the 1970s and 1980s, a proliferation of training centres prompted the Government to privatise them. However, many closed in the following industry slump.
Today, the Underwater Centre in Fort William is one of a handful around the globe offering a range of industry-related commercial diving training.
Previous owners went bust during a dip in oil prices, but the new owners took over more than two years ago, with an optimistic eye on an industry that they felt was on the way back up.
However, diving jobs are not all oil rigs and North Sea gas. Divers are employed in underwater archaeology (the UK is surrounded by shipwrecks), in the media (for film and nature programmes) and by the police to sweep waterways for dead bodies and and in search of evidence.
Employers include Network Rail, which needs divers to check the underwater parts of bridges, and Scottish and Southern Electricity, which requires regular health checks on its dams. Piers, canals and rigs all have to be checked for wear and tear from below the surface.
Steve Ham, marketing manager for the Underwater Centre, is keen to point out that diving is not actually a job in itself.
"Diving is just the way to get to work. You need skills once you get there, such as welding and the ability to test whether a structure is rusty or falling apart."
The two types of diving the centre trains in are saturation and air assisted. With air assisted, divers are fed oxygen from the surface through an umbilical cord down to 50 feet. In saturation, divers descend in a pressurised diving bell to reach far greater depths. In preparation, they live for up to a month under pressure in a special chamber. It can take five days to return their bodies gradually to normal surface pressure - longer than it takes astronauts to return from the moon. Scuba diving, however, forms a relatively small part of commercial diving.
"It is amazing how busy the diving industry is at the moment," Mr Ham says.
"There is a requirement for another 800 divers over the next two to three years, and there are only three schools that teach it.
"We are doing back-to-back courses - we are fully booked until February next year."
The centre also trains people to pilot ROVs - underwater robots with a camera attached, operated by pilots on the surface - and there is demand for a further 1,200 in the next two to three years.
To satisfy that demand, the centre is planning to expand student numbers and widen its range of courses. It may set up links with other educational institutions to help.
"We have discussed links with education bodies because we see a need for creating professional education," explains Mr Ham. "Commercial diver training is guided by the Health and Safety Executive, but the industry needs more than people who can just dive in safety."
"We see great potential in introducing more professional education, for example, a dive management degree, and we have had very initial dicussion with the University of the Highlands and Islands."
Key to the popularity of the underwater centre's courses is quick turnaround. "You can come with absolutely no experience and 13 weeks later you will be a professional diver," explains Mr Ham.
A qualified air diver in the North Sea can earn pound;400 a day, and a saturation diver up to pound;1,000 a day, thanks to a 43 per cent pay rise negiotiated by the RMT last year. The financial lure is attracting people from many walks of life, including women.
"Quite often it is people who work with their hands, such as car mechanics or engineers," he says.
"But if you are determined, if you are focused, have a good attitude and are prepared to put up with the hard conditions, it could be the job for you."
Former joiner Alan Robertson, 44, decided to take up diving after a foray into property development was scuppered by falling property prices in his home town of Inverness.
"I've been scuba diving on holidays and I always fancied it," he says. "I dived before quite a lot, so air diving is probably a bit easier. Some of the guys had never done it, so it is brave of them to go straight into air diving.
"It is safer - you have a lot less to worry about and you are never going to run out of air."
Alan is hoping to get work as a saturation diver in the oil and gas industries, once his training is complete.
Another student has been air diving for 10 years and came to Fort William for a saturation diving course to increase his earning potential. He did not want to be named, as his current employer does not know he's looking to change jobs.
The 33-year-old worked in a government office in London after graduating with a degree in geography. A keen scuba diver, he was told if he wanted to make a career out of diving, he would earn more if he trained commercially.
He also completed a Masters in marine science at Heriot-Watt University's Orkney campus.
Of his dramatic career change, he says: "I was travelling on the Tube one day in July and it was hot and packed and I thought: 'This is rubbish'."
A decade later, though, he has seen a marked decline in the number of divers: "There were definitely far more divers then."