Abstract : After undertaking research to determine the influence of weather on replenishment and carrier operations, it became apparent that deficiencies in the data concerning ocean wave characteristics exist. Before any substantial progress in the study of replenishment and carrier operations can be made, improved and standardized ocean wave observations must be available. This report is written primarily for quartermasters who are generally responsible for the observing and reporting of ocean waves aboard U.S. Navy ships. It presents, in a concise form, the characteristics of ocean waves and explicitly points out the differences between wind waves and swell. Standard methods for observing wave direction, period, and height are then presented.