The first known measurement of the attenuation of sound in deep water at frequencies below 1 kHz in the South Pacific Ocean is described. The receiver was situated off the east coast of the North Island of New Zealand. It was found that the attenuations are in most cases comparable with the values of attenuation measured in the North Pacific Ocean and the Atlantic Ocean between Bermuda and South America. However, on one of the paths over which the attenuation was measured, there was an abrupt change in the quality of sound transmission, which is thought to be a result of the path crossing the Subtropical Convergence; south of this discontinuity the attenuations were found to be comparable with those obtained previously in the Southern Ocean.