The instructional subject matter included such topics as the use of safety 

 techniques and equipment; the proper use of scuba gear; the physical laws of 

 various gases; the injuries unique to the diving community, and their causes, 

 symptoms, and remedies; the recognition and management of dangerous marine 

 animals; and safe methods of diving from small boats. The physician-students 

 were required to demonstrate a series of swimming skills. They then embarked 

 upon open-water dives in which they were instructed in such scuba techniques 

 as buddy breathing, equalizing of pressure in the ears during descent and in 

 the lungs during ascent, point-to-point swims by compass, diver assistance in 

 an emergency, and night diving. 



Informal instruction in hyperbaric medicine was offered throughout the project 

 to the TEKTITE medical staff by Dr. Beckman as part of the medical program. 

 This instruction was augmented by the practical experience of having to cope 

 with the sequence of medical difficulties that arose in the habitat, during 

 decompression, in base camp, and among the support divers. The medical staff 

 was also given selected texts to read pertinent to diving theory and practice 

 and to diving medicine. 



Mission-Connected Medical Experiences 



The TEKTITE II 50-ft missions were intended to validate the basic concepts and 

 values upon which the decompression tables used in TEKTITE I had been calculated, 

 The evidence offered by laboratory tests and the experience of the TEKTITE I 

 aquanauts was statistically invalid because of the small number of subjects 

 involved in each. The 50-ft missions were also intended to test the safety of 

 the ascent-descent excursion limits established in the earlier program. 



Decompression sickness during excursion dives from the habitat : 



During the two-week training period preceding each dive, the aquanauts received 

 instruction, as has been said, in saturation diving and in the limits of 

 excursions from the habitat depth that were believed to be safe--descent to 

 100 feet of seawater (FSW) for a period of four hours on an air breathing 

 mixture, and ascent to 25 FSW, also for a period of four hours on air. 



The aquanauts were further instructed that, if both ascent and descent 

 excursions were to be made during any 12-hour period, the ascent excursion 

 should precede the descent excursion. Moreover, no descents were permitted 

 from the habitat on the day that decompression to surface pressure was to 

 begin. 



The excursion limitations had been set after very limited testing (owing to 

 the lack of sufficient funds) prior to TEKTITE I. The limits thus set were 

 therefore not expected to prove safe for all subjects observing them. 



During the course of the 11 TEKTITE II 50-ft missions, only three instances 

 of bends sjTnptoms occurred as a result of excursion diving, the first two of 

 them in Mission 2-50. One of the latter subjects who had experienced a "hit" 

 in excursion diving in TEKTITE I (which was not properly identified until 

 prebriefing prior to Mission 2-50) followed the identical excursion pattern 

 in TEKTITE II, He descended to 65 FSW for 30 minutes and then ascended to 

 25 FSW. Shortly after reaching the shallower depth, he experienced bends 

 pain in the knee, the same one that had been affected in TEKTITE I. The pain 

 remitted upon return to the habitat, but not as quickly as it had done the year 

 before. (The only other difference between his TEKTITE I and II experiences 



IX-8 



