Partial abstract: A 1:100-scale (undistorted) hydraulic model, reproducing Mission Bay Harbor, approximately 3 miles of shoreline, and sufficient offshore area to permit generation of the required test waves, was used to investigate the arrangement and design of proposed structures for (a) improving hazardous entrance conditions, (b) reducing surge inside the harbor, and (c) eliminating potential flood hazards. The original proposal for harbor improvement consisted of a 2,200-ft-long offshore breakwater. The proposed structures for river flood control consisted of (a) a 1,200-ft-long weir in the middle jetty, (b) various south jetty extensions, and (c) diversion dikes on the middle jetty.