Volume backscattering strengths averaged over four depth intervals and at the frequencies 3.5, 6, 8, and 12 kHz were measured at a number of stations in the South China Sea and the eastern region of the equatorial Indian Ocean. Measured values ranged from −91 dBrem−1, which occurred at 3.5 kHz, to −61 dBrem−1, which occurred at 8 kHz. On the average, the scattering was a maximum in the depth interval 0