A Review of Health and Safety Of Deep Divers
Authors: Wise Robert A. 
Published: December 2007

There are great technological problems to surmount in sending men to work on the sea floor, problems connected with temperature control, voice communication, visibility, psychological forces. But unless a man can breathe adequately get the right amount of oxygen in and the proper amount of carbon dioxide out and retain his dexterity and clear-headedness, solving the other problems will be useless.

Introduction
Until the last few decades, man's subsea diving depth has been limited to about 100 ft. Recently, commercial interests in the oceans, along with naval development, have been responsible for a rapid extension of depth. In particular, the offshore petroleum industry, which accounts for some 80 percent of commercial diving, has been rapidly moving to increasingly deeper water. Twenty years ago, off shore drilling and production was limited to water depths of approximately production was limited to water depths of approximately 50 ft. Today, production has been established in water depths of more than 370 ft; exploratory drilling operations have moved to water 1,500 ft deep, and a discovery has been made beyond 1,000 ft. (Fig. 1 indicates present maximum depths of different petroleum industry activities.) At the same time, diving is routinely conducted to depths of 300 to 500 ft; experimental dives have been conducted in the open sea to depths of more than 600 ft; and simulated laboratory dives have been conducted to pressures equivalent to 1,500 ft.
Oil operations will continue to extend to deeper water, and as this occurs, extension of man-in-the-sea's working depth can be safely accomplished at reasonable cost. However, a number of medical and engineering developments are necessary if this is to occur. These challenges include the development of life support systems to supply the diver with properly controlled breathing mixtures, clothing to protect him from the cold subsea environment, and pressure chambers to allow him to be properly compressed and decompressed to and from the pressures encountered in the sea.
These improvements in the safe and efficient use of divers will require the use of the nation's best scientific talent in the fields of engineering, medicine, physiology, pharmacology, biochemistry, behavior physiology, pharmacology, biochemistry, behavior science and computer science. To date, diving developments have been largely the concern of diving contractors, navies of the world, and several universities. But the operator who needs extended diving capability to help him exploit deep-water mineral resources should be aware of physiological problems and the requirements for solving them.
The objectives of this paper are to describe the important deep-diving physiological concerns. At the same time, we hope to acquaint the user of diver services with the basic concerns of diving safety and thus prepare him to work with diving contractors to insure safe diving operations; we also hope to indicate to the offshore industries some fruitful areas for the best research use of money and talent.

Method of Work Diving
Diving methods and procedures have changed greatly as man-in-the-sea activities have moved to deeper waters. Generally, these changes have been necessary to improve diver safety and to make deep diving more economical. At depths to about 60 ft, diver bottom time is limited by considerations of safety and endurance.
JPT
P. 294