The last paragraph of Operating Principles talks about just that. Finally, it must be remembered that the bathyscaph is not a submarine. It has neither the mob

The last paragraph of Operating Principles talks about just that. 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 investigations 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.