The Collaborative International Dictionary of English v.0.48:
bathyscaph \bath"y*scaph\, bathyscaphe \bath"y*scaphe\n. navigable deep diving vessel for underwater exploration. Syn: bathyscape. [WordNet 1.5]WordNet (r) 3.0 (2006):
bathyscaph n 1: navigable deep diving vessel for underwater exploration [syn: bathyscaphe, bathyscaph, bathyscape]