A 1:100-scale (undistorted) hydraulic model of the western portion of Cleveland Harbor, which was used initially to determine effects of proposed improvements at the Cleveland Harbor main entrance with respect to ship maneuverability, wave and current action, and riverflow conditions was used to determine the effects of various improvement plans with respect to wave and current action at Edgewater Marina, located at the western boundary of Cleveland Harbor. Improvements at Edgewater Marina consisted of modifications to the harbor entrance and channel, installation of new breakwaters, modifications to the existing structures, and installation of rubble absorbers in the harbor. A 120-ft-long wave generator and an Automated Data Acquisition and Control System were utilized in model operation. It was concluded from test results that: A.) For existing conditions, rough and turbulent wave and current conditions existed in the harbor entrance and basin during periods of storm wave attack. B.) Of the improvement plans tested with the new breakwater installed at the existing entrance and the east breakwater raised to an elevation of +9.5 ft (Plans 1-1I), Plan 1H appeared to be optimal with respect to wave protection and construction costs. C.) Of the improvement plans tested with absorber installed adjacent to the entrance structures and the east breakwater raised to an elevation of +9.5 ft (Plans 2-2C), Plan 2C appeared to be optimal with respect to wave protection and construction costs. D.) Of the improvement plans tested with the existing entrance closed and raised to an elevation of +9.5 ft, the east breakwater raised to an elevation of +9.5 ft, and a new entrance installed through the Cleveland Harbor west breakwater (Plans 3-3C), Plans 3B and 3C appeared to be optimal with respect to wave protection in the marina; however, wave heights in the Cleveland Harbor West Basin increased significantly. E.) Of the improvement plans tested with the curved portion of the Edgewater breakwater replaced with randomly placed stone and the east breakwater raised to an elevation of +15 ft (Plans 4-4E), Plans 4C and 4E appeared to be optimum with respect to wave protection afforded and construction costs. F.) For any improvement plan to be effective (i.e., wave heights reduced to 1.0 ft or less in the marina) a portion of the existing Edgewater breakwater (that portion adjacent to the existing sheet-pile wall) will have to be either raised or increased in width. G.) The installation of any of the optimal improvement plans tested should reduce or eliminate hazardous wave-induced currents in the basin during the boating season (spring, summer, and fall).