An investigation into the long‐range propagation of sound in shallow, isovelocity water was carried out using an extensive area of the continental shelf off the west coast of New Zealand. The results obtained showed that a classic example of normal‐mode propagation in shallow water was involved. The values of attenuation obtained and the general behavior of the attenuation as a function of frequency are comparable with other shallow‐water areas. Other characteristics of the propagation mechanism can be explained in terms of depth variation and layering of the bottom.