sentences:  In the 1950s through 1970s scientific diving in the U.S. was conducted by various organizations using similar but informal self-regulated standards.Professor George Bass of Texas A & M University pioneered the field of underwater archaeology from 1960, mostly in the Mediterranean 
  
  In 1975 the United Brotherhood of Carpenters and Joiners of America petitioned for an emergency temporary standard be issued with respect to occupational diving operations.The ETS issued on June 15, 1976 was to be effective from July 15, 1976 but was challenged in the US Court of Appeals by several diving contractors, and was withdrawn in November 1976.