Improving the health of Filipino divers is the aim of research under way at Bangor University's department of radiography education. Decompression sickness is a major problem among Asian divers who, unlike their western counterparts, have little access to decompression chambers or medical assistance.
The problem is exacerbated by the length of time Filipinos stay under water. Westerners would spend only 17 to 22 minutes at depths of 100 feet. But the Filipinos will stay at that depth for three hours. And they often undertake three such dives a day.
Unsurprisingly therefore they are subject to the bends and a related bone disease called dysbaric osteonecrosis.
To discover more about these conditions in the Philippines, radiography researcher Peter Dudley spent the past month on the Philippine island of Nocnocan where 100 men earn a meagre living diving for fish.
"I was amazed to discover their approach to treating decompression sickness," Mr Dudley said. "They just buried victims up to their necks in sand for 48 hours. But surprisingly many of them seem to recover and did not suffer permanent paralysis, as can happen with someone who's badly affected by the bends."
Bone disease was common, with up to 40 per cent of the divers complaining of pains in their bones.
In the West, anyone with the condition would be advised to stop diving but on Nocnocan they continue and so could end up crippled with broken joints and damaged long bones.
According to Mr Dudley, "they are putting their lives at risk". Diving accounted for five deaths there last year. Many more are suffering from diving-related injuries. But Mr Dudley was unable to calculate how many because his X-ray equipment was impounded by Filipino customs.
Such equipment is essential if the bone disease is to be diagnosed in its early stages. And even then it can take up to three years after a critical dive for bone damage to appear.
Mr Dudley plans to return to the Philippines in June to reclaim his equipment and to X-ray the divers of Nocnocan. Then he will have a clearer picture of the actual incidents of bone disease in the Philippines.
He is convinced that diving-related illnesses are widespread among the population of the 7,000 tropical islands which make up the Philippines. On Nocnocan, out of 2,000 divers, former divers and their families, he met only one person who was over the age of 55.