hydronaut

[ hahy-druh-nawt, -not ]
/ ˈhaɪ drəˌnɔt, -ˌnɒt /

noun

a person trained to work in deep-sea vessels for research and rescue purposes.

Origin of hydronaut

An Americanism dating back to 1965–70; hydro-1 + (aero)naut

British Dictionary definitions for hydronaut

hydronaut
/ (ˈhaɪdrəʊˌnɔːt) /

noun

US navy a person trained to operate deep submergence vessels

Word Origin for hydronaut

C20: from Greek, from hydro- + -naut, as in aeronaut, astronaut