Proceedings of the 9th international conference organised by the Institution of Civil Engineers and held in Edinburgh on 16 to 18 September 2009. These conferences, sponsored by the Institution of Civil Engineers for more than 25 years, discuss the state of the art in analysis, design and construction of breakwaters and other types of coastal structures, including interactions between coastlines and structures, and vice versa. This 9th conference has continued to reflect more generally holistic approaches to the use of coastal structures, with strong emphases on the wider influences on design, construction and use. This now includes the use of nearshore structures to extract wave or tidal stream power, as well as structures to protect coastlines or harbours. It was therefore particularly appropriate that this conference was opened by Jim Mather MSP (Minister for Energy in the Scottish Government), assisted by Phil Gilmore (Marine Scotland) and Paul Jowitt (ICE President-Elect). For the first time in Edinburgh, the 9th Breakwaters & Coastal Structures conference has substantially expanded the number and coverage of papers, and has added a local innovation in the conference “fringe” – a set of rapid-fire papers on developing issues, current projects and research of specialist interest. With 113 main session papers, supplemented by 15 fringe papers, this conference was 2½ times larger than before, the major expansion being in the design and performance of near-coast renewable energy devices, structure foundations, and wider issues associated with managing shorelines. There have been many conf erences on methods to extract marine energy, but this event has brought together device developers and the engineers who must design, construct and maintain the infrastructure to support those devices. Contents: Volume 1: Conference opening. Design optimisation. Breakwaters. Improving existing facilities. Use of concrete in maritime engineering. Innovation in construction. Coastal management. Armour unit placement. Erosion risk. Development of ports and harbours. Closing plenary: adapting to change. Planning and renewables. Seawalls. Renewable schemes. Volume 2: Beach structure interactions. Foundations and renewables. Coastal defence. Renewable schemes. Shorelines: adapting to change. Shorelines: measuring change. Hydrodynamics. Revetments. Metocean. Overtopping. Breakwater stability. Breakwaters, coastal processes and marine structures.