Until the early 1950s, navies and other organizations performing professional diving were the only providers of diver training, but only for their own personnel and only using their own types of equipment.
Do ranih 1950-ih, mornarica i druge organizacije koje su obavljale profesionalne zarone jedini su pružali ronilačke treninge, ali samo za svoje osoblje i isključvo se primjenjivala njihova oprema.