The use of hydraulic models in coastal sedimentation studies dates back more than 60 years. To the best of the writer's knowledge, the first such model was of the tidal portion of the Mersey River in England, and was constructed and operated by Professor Osborne Reynolds in the year 1887. Data obtained from the model tests by Professor Reynolds were used in the location and design of navigation channels from the sea to the port of Liverpool. Since the time of Professor Reynolds, numerous models have been used in this and other countries for studies of coastal sedimentation problems. The first such study made by the waterways Experiment Station was of Winyah Bay, South Carolina in 1933, and was followed by studies of Ballona Creek outlet near Venice, California; Galveston Harbor, Texas; Absecon Inlet at Atlantic City, New Jersey; the Umpqua River entrance in Oregon; Lynnhaven Inlet near Norfolk, Virginia; and many others. This paper covers in a general way the types of coastal sedimentation problems subject to model analysis, the types of models used, model instruments and appurtenances, field data requirements, adjustment and verification of models, testing of proposed improvement plans, the analysis of test results, and the limitations of models.