Since a breaking wave has such a dramatic effect on the bubble population over such a brief period of time, it is necessary to acquire a bubble profile in a fraction of a second. A high-speed bubble-sizing technique has been developed that should have the capability of accurately determining bubble populations during breaking waves. Testing was performed in a pool 3 m in diameter and 1 m deep. An artificial bubble cloud was created through the use of compressed air and hypodermic needles. A three-transducer system was used to determine the existence of various bubble sizes. The system developed to date was able to acquire an average bubble spectrum from 2.5–6 kHz in 0.1 s. Through the use of the double frequency technique, there would be very little or no contribution from nonresonant bubbles at each frequency of interest. The results of the system were compared to the data obtained by listening to ambient bubble noise with a transducer and from photographic population counts. These comparisons demonstrated the effectiveness of this technique. [Work supported by ONR.]