Abstract
Progress in the United States in the study of oceanic internal waves has continued in both observational and theoretical areas. Whereas the theories are becoming more sophisticated all the time, their bearing on the observations remains peripheral and speculative. This state of affairs is primarily because of the lack of definitive field observations and the ambiguities that arise in almost all real data. Most work, theoretical and observational, falls into several broad, overlapping categories, which we will examine here.