at a minimum, a valid certificate of medical fitness to operate in a pressurized environment, and a certificate of medical fitness to dive. Training standards for diver medic are described in the IMCA Scheme for Recognition of Diver Medic Training. Ethical and medicolegal issues Experimental work on human subjects is often ethically and/or legally impracticable. Tests where the endpoint is symptomatic decompression sickness are difficult to authorise and this makes the accumulation of adequate and statistically valid data difficult. The precautionary principle may be applied in the absence of information allowing a realistic assessment of risk. Analysis of investigations into accidents is useful when reliable results are available, which is less often than would be desirable, but privacy concerns prevent a large mount of information potentially useful to the general diving population from being made available to researchers. History of diving medical research Timeline November 1992: The first examination for certification in Undersea Medicine by the American Board of Preventive Medicine. November 1999: The first examination for Undersea and Hyperbaric Medicine qualification. Notable researchers Arthur J. Bachrach Albert R. Behnke Peter B. Bennett Thomas E. Berghage Paul Bert George F. Bond Alf O. Brubakk Albert A. Bühlmann Carl Edmonds William Paul Fife John Scott Haldane Robert William Hamilton Jr. Leonard Erskine Hill Brian Andrew Hills F.J. Keays Christian J. Lambertsen Joseph B. MacInnis Simon Mitchell Richard E. Moon František Novomeský John Rawlins Charles Wesley Shilling Edward D. Thalmann Richard D. Vann James Vorosmarti R.M. Wong Robert D. Workman Research organisations See also References Further reading External links Scubadoc's Diving Medicine Online Diving Diseases Research Centre (DDRC) Diving Medical Literature SCUBA Diving and Asthma infos scuba diving restrictions – free download of complete text Military medicine