süvavee rõhu mõjust kaitstud vabalt sukelduv, iseliikuv ja süvamerre sukeldatav mõõtekompleks-seade, mis koosneb ka meeskonnakabiinist, okeanograafiliste mõõtesuuruste mõõtmiseks
free-diving, self-propelled deep-sea submersible, consisting of a crew cabin similar to a bathysphere, but suspended below a float rather than from a surface cable, as in the classic bathysphere design
Laskumiseks täidab batüskaaf õhupaagid vastava koguse mereveega, kuid ei saa üleujutatud paakides olevat vett suruõhuga ümber paigutada, et tõusta, sest veesurve sügavustel, mille jaoks batüskaaf on mõeldud töötama, on liiga suur. Selleks kasutab batüskaaf rauast haavlikonteinereid, mis on kogu sukeldumise ajal põhjas avatud, kusjuures rauahaavleid hoiab paigal kaelas olev elektromagnet. Haavlite vajaliku koguse väljutamine elektromagnti abil on tõrkekindel, ja kui tekib elektrikatkestus, siis tõus on automaatne.
To descend, a bathyscaphe floods air tanks with sea water, but unlike a submarine the water in the flooded tanks cannot be displaced with compressed air to ascend, because the water pressures at the depths for which the craft was designed to operate are too great. Instead, ballast in the form of iron shot is released to ascend, the shot being lost to the ocean floor. The iron shot containers are in the form of one or more hoppers which are open at the bottom throughout the dive, the iron shot being held in place by an electromagnet at the neck. This is a fail-safe device as it requires no power to ascend; in fact, in the event of a power failure, shot runs out by gravity and ascent is automatic
