Breaking waves produce large numbers of gas bubbles immediately below the ocean surface. The effect of these bubbles on the sound speed is important in studies of sound propagation in the upper ocean. Recent studies have also indicated that the bubbles can play a major role in gas exchange through the air‐sea interface. The bubbles are also being used as passive tracers to study the flow field in the upper ocean. For most studies involving the bubbles, it is of importance to determine the actual size distribution of the bubbles. Here, some results from the SWAPP and Critical Sea Test experiments, where a six‐frequency acoustic backscatter technique was used, will be presented. Variability in the bubble size distribution will be related to the “age” of the bubble clouds as well as to the presence of coherent flows in the ocean, such as Langmuir circulation.