aboard MIZAR using a system previously described by 

 Patterson^. 



Underwater optical sensors are the only presently 

 available devices with the ability to classify bottom 

 contacts, and therefore they remain the prime tool for 

 ocean floor search. As a result of the short ranges 

 inherent in such sensors, the search of any large area 

 will entail many hours spent close to the bottom. The ' 

 MIZAR left Norfolk on 2 June I968 and completed the 

 search on 7 November I968. This is about 38OO hours 

 of which 2500 were spent in the search area. The towed 

 camera system was close to the bottom, taking photographs, 

 for 1000 hours or 40^ of this time. This percentage could 

 have been increased if the time in the area had been spent 

 solely for photographic operations. 



Observers in a manned submersible can see no farther 

 than the camera. No presently available submersible can 

 even approach a kofo duty cycle. The cost of building and 

 operating a deep submersible is sufficient to pay for a 

 number of towed systems such as that on MIZAR. For these 

 reasons, a towed camera system is and will remain the 

 optimum ocean floor search system for years to come. 



SUMMARY 



This paper has demonstrated that the successful search 

 for the SCORPION represents a significant improvement of 

 techniques and equipment over those used to locate the 

 THRESHER in 1964. The magnetometer was the most useful 

 of the non-optical sensors. The acoustic systems were of 

 little use and this is unfortunate as they have greater 

 range potential than other types of underwater sensors. 

 The wide angle lens systems and large capacity cameras de- 

 veloped since the end of the THRESHER search have been 

 proven to be ideal search tools. However, these cameras 

 lack necessary resolution, so that after the submarine is 

 located it Is necessary to supplement them with narrow angle 

 cameras. In the future it may be possible to use larger film 

 sizes in order to obtain the required resolution without 

 sacrificing angular coverage. Finally, it is shown that towed 

 systems are economical and can be operated at high duty cycles 

 which gives them some advantage over manned submersibles as 

 deep ocean floor search tools. 



48 



