He will be relatively weightless, which might seem to be an advantage when it comes to moving about, but this presents real problems. If he is required to exert any great physical pressure to turn a wrench or wield a hammer, it is all too likely that he will turn, the wrench remaining where it is. Underwater vision is severely restricted by the tunnelling effect of refraction through his face mask, if indeed he is fortunate enough to be working under conditions that allow him to see anything. He is often required to work under conditions of zero visibility, operating by touch alone.
A commercial diver will expect to have to work under very cold conditions. While suits heated by a constant flow of warm water may be available, they are by no means the rule. Similarly, although a wide range of diving gloves exists, none appears to be really adequate under near-freezing conditions. Communication presents a further problem. The diver's voice is likely to be distorted by pressure and even further distorted if he is breathing an oxyhelium mixture. Helium unscramblers help, but are very far from perfect.
Having successfully completed a job under water, the problems are far from over. As the diver breathes air or oxyhelium at pressure, the nitrogen from the air or the helium from the oxyhelium is absorbed by his blood and body tissue. If he surfaces too rapidly, the gas forms bubbles in his tissue and bloodstream, leading to decompression sickness, otherwise known as 'the bends'. These may range from relatively minor joint pains (the niggles) to symptoms associated with breathing (the chokes), and to impairment of the central nervous system, producing motor disability (the staggers), pain, and possibly death. The bends can be avoided provided the diver surfaces slowly enough, but if he has been working at a depth of several hundred metres, decompression is likely to take a matter of days. In order to cope with this problem it is common for divers having a major job to do at depth to live at pressure in a decompression chamber, being transported to and from the job every day by means of a submersible decompression chamber that can be locked onto or detached from the main chamber on board the ship or rig. After a week of living at pressure the diver will spend the next week or so decompressing before taking some well-earned leave.
Socially, a diver's life is likely to be a rather curious one: unless he limits himself to inshore harbour work, periods out on an oil rig or pipe-laying barge are likely to alternate with periods of leave. If he is working on a rig, he may have long periods of inactivity followed by an emergency and a requirement suddenly to dive to a considerable depth. If he is working on a barge, he may be required to operate under saturation for many days. Under these conditions it is essential to be able to maintain good relations with fellow divers.
Diving is a dangerous occupation even if the diver takes good care to breathe the right gas mixture and maintain the right working temperatures and the appropriate decompression schedule. He is working in an environment in which accidents are all too common, even out of the water. Under water, a minor accident can be fatal. Divers are very well paid — and so they should be. See also nitrogen narcosis.
(Published 1987)
— Alan Baddeley
- Bibliography
- Godden, D., and Baddeley, A. D. (1979). 'The commercial diver'. In Singleton, W. T. (ed.), The Study of Real Skills: Compliance and Excellence, vol. ii.
