ABSTRACT 



Sealab II operations conducted by the Office of Naval Research as a part 

 of the man-in-the-sea task of the Deep Submergence Systems Program was 

 an interdisciplinary investigation into the usefulness of ocean floor habita- 

 tion by the measurement of the ability of man to do useful work while living 

 as a saturated diver in equilibrium with the ocean-floor pressure. 



Ocean-floor tasks of the 28 Navy divers and civilian scientists included 

 working dives for studying human physiology and performance, experimental 

 salvage techniques, biological and physical oceanography, and the evaluation 

 of the undersea habitat and associated diving equipment. 



The Sealab II operation was conducted between Aug. 28 to Oct. 14, 1965, 

 3000 ft off Scripps Pier at La Jolla, California, in a depth of water of 205 ft. 

 Using a synthetic breathing gas of helium, oxygen, and nitrogen, each of the 

 three aquanaut teams lived underpressure approximately 1 5 days in an ocean- 

 floor habitat, making forays into the 48° F, 5 to 30 ft visibility bottom waters 

 for periods ranging from a few minutes to an extended dive of 3 hours. Ex- 

 cursion no-decompression dives to 266 ft and 300 ft were accomplished. Div- 

 ing from the habitat was accomplished using both semi-closed-circuit breath- 

 ing apparatus and hookah (habitat-connected-hose) breathing apparatus. A 

 decompression complex new to the Navy consisting of a personnel transfer 

 capsule mating with a deck decompression chamber was used for accomplish- 

 ing recovery and decompression of aquanauts. 



Sealab II demonstrated that: 



1. The concept of ocean-floor habitation to accomplish a wide range 

 of salvage and scientific tasks is compatible with man's ability to 

 perform useful work at these depths. 



2. No significant short-time physiological changes occur which re- 

 sulted in deterioration of the aquanauts physical condition. 



3. There is a degradation of human performance which increases 

 with the complexity of the task being accomplished. 



