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Vertical structures of hydrodynamics under wave conditions were investigated using live plants in a large-scale wave flume. The effect of vegetation on hydrodynamics were analyzed for regular wave cases. The interaction of waves and emergent vegetation under regular waves significantly affect wave-induced motion and turbulence intensity. Coastal vegetation motion affected the water particle kinematics so that the vertical distribution of water particle velocity showed a large deviation from linear wave theory. Also, the vegetation motion increased turbulence intensity in the middle of water column and this caused a different vertical distribution of turbulent kinetic energy compard to the control case with no vegetation. In addition to the turbulence kinetic energy level, the vegetation changed the anisotropy characteristics of turbulence, decreasing vertical turbulent component.

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St. George Island, Alaska is located in the Bering Sea more than 320 kilometers (200 miles) north of the nearest Aleutian Island. During original design and construction of the fishing harbor at St. George Island in the early 1980’s, stone large enough for a conventional breakwater was not available to quarry on the island, so the project utilized a berm breakwater approach with the available local stone. The long-term performance and service life of the berm breakwaters is reviewed in this paper. Construction of the berm breakwater was completed in 1987 and the breakwaters remained functional for nearly 20 years with little maintenance. In the winter of 2015/2016, approaching 30 years since initial construction, significant damage occurred during a winter storm. Repairs utilized a berm breakwater approach similar to the original design. Repairs were completed in 2 phases due to the short construction seasons at the project site.