The acoustic properties of deep scattering layers were examined using explosive sources at a few hundred sites in the main basins of the North and South Atlantic and the North and South Pacific, in the Labrador, Norwegian, Mediterranean, and Caribbean Seas, and in Baffin Bay. Representative day and night spectra of column strength are presented for these areas in the frequency band 0.8–25.6 kHz along with estimates of the effective radii of the swimbladders of the dominant scatterers. The spectra tend to fall into homogeneous groups, with the most pronounced changes in type taking place near known faunal boundaries. In mid‐ocean, in the North and South Atlantic and the South Pacific, scattering is high near the equator and at mid‐latitudes, with considerably lower values in between. Very low scattering strengths are also found in the cold waters at high latitudes in both hemispheres. In a number of cold water areas in the northern hemisphere there is a pronounced peak in sound scattering at low frequencies, caused by scatterers with effective radii of swimbladders of 1 cm or greater. As some of these relatively large scatterers are probably commercial fish, it appears that a measurement technique similar to that used in this investigation would be a useful tool in resource management of commercial fisheries.