16 MAJOR PROGRAM AREAS 



HUMAN PERFORMANCE 



The purpose of the human-performance program was to make an overall assessment of 

 man's behavior while living in the sea. The program was designed not only to determine how 

 well man can perform scientific tasks, but also to study broader aspects of adaptation to life 

 and work in the hostile undersea environment. 



Psychomotor tests used during the program were designed to measure the application of 

 maximum force (strength test), manipulative dexterity, eye-hand coordination, and the coopera- 

 tive assembly by four divers of a three-dimensional configuration. On most of these tests, 

 data were obtained on dry land, in shallow water, and during submersion in Sealab. 



The program also included auditory and visual tests. Predive and postdive hearing tests 

 were administered to each diver. Data were collected in the water on color and form dis- 

 crimination, and the optical properties of light transmission as well as the observation of 

 underwater lights. Results were also obtained on the ability of the divers to perform mental- 

 arithmetic tests, both before and during the submersion period. 



In addition to the specific tests described above, the men were under continual surveillance 

 during submersion by closed-circuit television and open audio channels. The behavior of the 

 men was systematically observed and recorded. These data included eating and sleeping hab- 

 its, activity levels, variation of mood, morale, motivation, and the general spirit of coopera- 

 tion. Following the submersion period, each diver completed questionnaires and medical ex- 

 aminations, and was interviewed. 



Results showed that in spite of all the obstacles and dangers present during Sealab 11, an 

 unprecedented amount of useful work was done. While some of this work possibly could have 

 been performed from the surface, a diver, with his inherent flexibility for on-the-spot decision 

 making and planning, was the essential element in the program. Although some degradation of 

 work performance occurred, the aquanauts' performance of scientific and operational tasks 

 demonstrates clearly that man can live in harmony with the hostile undersea environment. 



EXPERIMENTAL WET SUITS 



The principal objectives of the experimental wet-suit program, as detailed in Chapter 37, 

 was to evaluate the concept of supplementing body heat with Joule heating to maintain thermal 

 balance during prolonged cold-water exposure. Eight experimental electrically heated 

 pressure-compensated wet suits were provided for Sealab II aquanauts (Fig. 11). 



Supplemental heat was generated by resistance wires powered either by a power cable 

 terminating in Sealab II or by silver zinc cells worn around the waist. Pressure compensation 

 was achieved through use of an open-cell natural rubber latex sponge sandwiched between thin 

 layers of solid rubber and injected with gas at depth to maintain normal thickness. 



Evaluations indicate conclusively that adequate thermal control can be realized with this 

 approach to protective suits for deep and prolonged cold-water immersion. 



HABITAT ENGINEERING EVALUATION 



The habitat engineering evaluation program (Chapter 38) presents a brief description of 

 Sealab H and associated systems and facilities, and their evaluation from an engineering stand- 

 point. The evaluation is based on observation, interviews with the aquanauts, and recorded 

 data, and includes hull, umbilical cord, baUast system, electrical system, breathing-gas sys- 

 tems, gas-sampling system, Arawak system, plumbing and sanitary system, communication 

 system, and data-recording system. In general, systems and equipment were satisfactory and 

 in most cases performed their designed functions, with a few notable exceptions. These ex- 

 ceptions include the food freezer, which would not maintain a sufficiently low temperature, the 

 dehumidifiers, which removed water at less than 25 percent of their rated rate, and the CO 2 

 scrubber, which was only 60 percent efficient. 



