Des Gorman, Drew Richardson, Bill Hamilton

and David Elliott

Diving industry, diving safety, mixed gases, policy, rebreathers, technical diving, training.

Introduction

The Society dedicated the 1996 Annual Scientific Meeting to a Workshop on emergent recreational diving practices, the so-called "technical diving", in recognition of the need for some pragmatic guidance in this area from an organisation with no commercial interest in the activity and as a responsible medical society.

The debate about technical diving has often been acrimonious, to the discredit of those involved, and has consequently distracted the attention of the debaters from the essential and necessary description of appropriate and relevant risk management. In addition, many commentators have become obsessed with the nature of the diver (e.g.. recreational versus employed) rather than paying attention to the nature of the diving. The issue is made more complex by uncertainty as to what is technical diving. Comprehensive definitions consequently include diving practices with widely divergent risks, thus a debate on the "safety" of technical diving per se becomes nonsensical.

The SPUMS Workshop on technical diving was free of both acrimony and rancour, indeed it was vigorous and entertaining, much to the credit of all those who presented papers, some of which are published in this edition of the Journal, and those who became involved in the debate. An acknowledgment here of the high quality of conference convening by Drs Guy Williams and Chris Acott is also appropriate. There were no written submissions.

The Society recognises, but does not necessarily endorse, technical diving. Such diving includes activities "outside" the conventional recreational limits of open-circuit demand scuba-air diving to 40 msw and often involves special techniques, equipment, gas mixtures and decompression procedures. Although a common definition of technical diving limits practice to those which involve a rebreather or a change in breathing gas during the dive (and hence excludes shallow enriched air diving and deep air diving), it is still considered that, for the purpose of risk management, technical diving is not a sufficiently specific term. This is because the types of diving referred to by this title are widely divergent in nature and risk. Instead, a consideration of each type of diving in isolation is necessary. It also follows that unique training and diving conduct measures are necessary for each type of diving activity.

The Society believes that the critical issue in assessing diving practice is the nature of the practice and not the intent or employment status of the divers.

The Society believes that before anyone undertakes any form of diving education or diving practice, it is important that:

The Society encourages recreational diving instructor agencies and dive organisations to evaluate critically all forms of diving technique that they intend to teach or practice. This recognises the current low rates of risk involved in conventional recreational diving as defined above. It is also reasonable to assume that effective control (i.e. risk management) of emergent diving techniques will result in the following:

Although the Society believes that occupational health and safety agencies should be encouraged to produce codes of diving training and practice, especially for operational dive organisation and planning, and technical codes for such things as equipment design, gas standards, gas mixing and testing, it is strongly recommended that these be seen as templates and that recreational diving groups become self-regulating. It is also recommended that this regulation should be visible in the form of standards and activities such as independent audits of incidents and accidents as part of an overall quality management program.

The Society is also concerned at the currently extravagant, and occasionally inaccurate, advertising of diving equipment and practice made by some manufacturers and training agencies and at the likely consequent misleading of the diving public. A self-regulated code of practice is recommended in this context. Members of the Society are also reminded that regulations concerning the accuracy of advertising do exist in most countries and that they should be active in alerting the relevant regulators.

Compressed air diving is not recommended deeper than 40 msw. Deep air diving below these depths in pursuit of individual or community records is considered foolish and should be discouraged.

Open-circuit demand scuba enriched air diving in accordance with proposed limits is not considered to represent a significantly greater risk to divers than conventional recreational diving practice as defined above. The PADI EANx (enriched air nitrox) program is acknowledged by the Society as being excellent and is recommended as a benchmark in this context.

Rebreathers currently available to the diving public may have operating instructions that are based on inappropriate assumptions concerning semi-closed diving apparatus and respiratory physiology. This could, and has been shown to, result in hypoxia and equivalent-air-depths that under-estimate the inert gas exposure. All semi-closed diving apparatus should be assessed for inspiratory gas content (at least over the oxygen consumption range of 0.5 to 3 litres/minute) by a suitable laboratory before sale to the diving public. Closed circuit diving apparatus also needs testing, but with a greater emphasis on technical reliability.

The first-aid management of an injured technical diver should be determined by the nature of the injury and will not differ from that recommended for divers in general.

Although the majority of technical divers developing a decompression illness will be well treated with a conventional treatment schedule such as USN 6, the Society encourages medical practitioners who may have to treat such divers to be aware of techniques such as oxygen-helium gas mixtures and saturation decompressions.