system, which would, of course, lead to obvious problems 

 if the pilot were not careful. The release of gasoline from 

 the small maneuvering tank, which is dependent on dis- 

 placement by sea water, is insufficient to appreciably slow 

 the craft's ascent once it starts to accelerate toward the 

 surface. 



The uncontrolled ascent is perhaps the most dangerous 

 part of the bathyscaph operation and the prime reason why 

 the surface ships must remain well clear of the diving 

 point. Standard procedure for the surface ships is to 

 stay at least 4000 yards from the diving point to avoid 

 collision with the ascending TRIESTE. It is hoped that, 

 at some time in the future, a portable sonar may be fitted 

 to the project work boat to allow it to "see" TRIESTE as 

 it ascends. Present procedure calls for keeping the work 

 boat at the diving point to maintain underwater telephone 

 communications with the bathyscaph. The intensity of the 

 underwater telephone signal is a fairly good gauge of the 

 proximity of the bathyscaph and, if the latter appears to 

 be too close, the work boat can move away from the diving 

 point. 



Finally, it must be remembered that the bathyscaph 

 is not a submarine. It has neither the mobility nor the 

 controllability of a submarine. Whereas a submarine may 

 be regarded as analogous to a dirigible or a blimp, the 

 bathyscaph may be considered to be a lighter-than-water 

 free balloon. The craft is at the mercy of currents and is 

 limited mostly to "elevator" type operations, such as inves- 

 tigations of the water column from the surface to the sea 

 floor and detailed studies of the sea floor at the base of the 

 water column. The bathyscaph type of configuration does 

 not lend itself to survey work. 



