384 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 64 



from a diesel-engine-like explosion following rapid flooding from 

 one end. 



Further activity in the search area this summer is already under 

 way. Complete systems combining acoustic, magnetic, and photo- 

 graphic techniques are being used, in connection with careful sonic 

 navigation. Trieste has been extensively rebuilt (this work had been 

 started prior to the Thresher accident) and has returned to the scene 

 as a far more rugged piece of seagoing machinery. Concurrently, 

 the Navy is preparing to implement a long-term development pro- 

 gram, based on work of special study group (the deep Submergence 

 Systems Review Group), which will give it capability in locating, 

 examining, and (in special instances) recovering objects on the deep 

 sea floor. This program will include the construction and outfitting 

 of small submarines having greater mobility, cruising range, and 

 work capability (though not greater operating depth) than Trieste. 

 Many marine scientists have long desired development of craft with 

 the observational, instrument-planting, and recovery capabilities that 

 these small submarines will have. It is unfortunate but true that 

 it has taken the Thresher tragedy to awaken many to our lack of ability 

 to investigate the deep sea — a lack not of basic knowledge of fruitful 

 tecliniques but of experience and equipment in being. Such capabili- 

 ties as we had a year ago grew directly out of our existing marine 

 research effort. The new capabilities which are being brought into 

 being as a result of last summer's work will help push forward our 

 ability to make even more fruitful exploration of the depths of the sea. 



