Here's a reference grasshopper

:
Scientific Diving Fatalities, 1970 through 1984--A Fifteen Year Review
Sharkey, P.; McAniff, J.
OCEANS
Volume 16, Issue , Sep 1984 Page(s): 517 - 520
Summary: Over the last three decades, american scientists have been using diving techniques in their research. The files of the National Underwater Accident Data Center were reviewed for references to diving for science. Twenty cases contained such references. Each case was examined and it was determined that ten might be loosely described as involving scientific diving. These ten were further investigated and six were found to fit a rigorous definition of diving science. Each of the twenty cases is presented and suggestions on how to avoid such incidents are made. Other data available on the frequency of nonfatal accidents is presented as is information on the population of diving scientists. The conclusion is reached that diving under the auspices of a diving control program similar to that pioneered at the Scripps Institute of Oceanography has an excellent safety record.
You'll have to take my word that the six remaining cases were divers who, though performing scientific tasks, were not diving under the auspices of a Scripps model diving safety program and who had not been through a 100 hour training program. In point of fact (if memory serves) all six were recreational divers involved in volunteer work for aquaria.