The results of 25 measurements of acoustic propagation to a range of 6 km in the ocean mixed layer, at frequencies of 4, 8, and 16 kHz, are summarized and compared with a number of propagation models. Within the mixed layer , the acoustic energies have considerable variability and are usually 10 to 20 dB less than the prediction of normal-mode theory for a perfectly reflecting surface (the shortfall increases with frequency). At 8 kHz, the (negative) correlation of acoustic energy with surface roughness (χ) is highly significant. The frequency dependence of the average data is similar to that predicted by the long-range version of the AMOS model but different to that predicted by the Baker model. At 16 kHz, the average energy is about 7 dB less than spherical spreading minus absoption; the cause of this attenuation is unexplained. Below the mixed layer (in the ’’shadow zone’’), the measured energies also have considerable variability. They are usually 10 to 15 dB greater than the predictions of normal-mode theory and decrease with frequency less rapidly than does the AMOS model. The measured ratios of below-duct to in-duct energies tend to increase with χ/λ; whereas, the Helmholtz–Kirchhoff theory of surface scattering predicts that, for values of χ/λ that correspond to the experimental values, the ratio should be a constant.