 The Navy Oceanographic Meteorological <unk> <unk> ( NOMAD ) buoy 's 6 @-@ metre ( 20 ft ) hull was originally designed in the 1940s for the United States Navy ’ s offshore data collection program . Between 1951 and 1970 , a total of 21 NOMAD buoys were built and deployed at sea . Since the 1970s , weather buoy use has superseded the role of weather ships by design , as they are cheaper to operate and maintain . The earliest reported use of drifting buoys was to study the behavior of ocean currents within the <unk> Sea in 1972 and 1973 . Drifting buoys have been used increasingly since 1979 , and as of 2005 , 1250 drifting buoys roamed the Earth 's oceans . 
