sentences:  A permanent standard for commercial diving became effective on 20 October 1977, but it did not consider the needs of scientific diving.The scientific diving community was unable to operate as previously, and in 1977 united to form the American Academy of Underwater Sciences (AAUS)
  
  After extensive negotiation and congressional hearings, a partial exemption to the commercial diving standards was issued in 1982, and was re-examined in 1984, leading to the final guidelines for the exemption which became effective in 1985 (Federal Register, Vol.50, No.