Integrated scattering‐strength measurements describing the backscattering of sound from the ocean volume in winter were obtained along a triangular track running west from the southern tip of Vancouver Island, British Columbia, thence south to Hawaii and then roughly northeast on a return leg to Vancouver Island. Thirty stations were occupied enroute, alternately at midnight and midday, weather permitting. The data were analyzed to yield spectral characteristics of the backscattering from various depth ranges at all station locations. The integrated scattering strength is seen to decrease and the daytime deep scattering layer to become shallower as one proceeds north from Hawaii. Differences between daytime and nighttime scattering and distinctive spectral characteristics associated with sub‐tropic and sub‐arctic water masses are illustrated.