In Sept., 1970, three COMEX divers worked twice a day for 8 days at 840 ft in the open sea, up to 3 hours at a time. The necessary methods and equipment were developed during a prior series of experimental simulated saturation dives.
Further improvement of these techniques has enabled man to work for extended periods of time, down to 1,000 ft even in arctic conditions.
In early 1970, the COMEX Co. undertook, as main operator, the series of saturation deep diving experiments known as the JANUS II operation. This experimental program, jointly sponsored by the Centre National pour l' Exploitation des Oceans and the French oil company, ELF-ERAP, was the logical follow -up to the JANUS I operation, which in 1968, had permitted us to develop and perfect the necessary methods and techniques for bringing saturated divers to work on a routine basis at a depth of 500 ft in the open sea.
The purpose of the JANUS II program was to extend the possibilities of this method to a depth in the range of 800 to 850 ft and to test its industrial practibility under real conditions in the open sea. The whole operation was divided into three main phases to ensure a logical progression toward the final objective of the program.
The first phase, which took place in April and May, 1970, in the pressure chambers complex of COMEX Hyperbaric Research Center, was mainly devoted to the detailed study of the various physiological parameters that governed the entire experiment. First of all, we verified the hypothesis that men, saturated at a simulated depth of 660 ft, could work twice a day for 2 hours at a time at a depth of 840 ft and return safely to their habitat, pressurized at 660 ft, without any intermediate decompression stops. This was realized through an 8-day saturation period by progressively increasing the duration of the 840-ft exposures from 1 to 2 hours, then shifting the evening dive to match the required working periods of 8 to 10 a.m. and 6 to 8 p.m. as shown in Fig. 1.
This basic hypothesis proved to be absolutely correct. At the same time, we verified that the total pressure exposure was physiologically harmless to the three divers and that their living and working capabilities were absolutely unaffected by these unusual conditions. This was effected by means of a series of intensive biological and physiological tests including (1) blood and urine sampling and analysis, (2) dietetic monitoring and control, (3) electro encephalographic and electrocardiographic monitoring, (4) respiratory measurements at rest and under effort by the use of a specially designed ergometric chair, (5) psychomotor tests and (6) study of the reflexes. This first phase additionally permitted us to start the evaluation of a new final decompression method intended to reduce significantly the duration of the return to normal atmospheric pressure.