The development of offshore wind power has become a pressing modern energy issue in which the UK is taking a major part, driven by the need to find new electrical power sources, avoiding the use of fossil fuels, in the knowledge of the extensive wind resource available around our islands and the fact that the environmental impact of offshore wind farms is likely to be low. However, there are major problems to solve if offshore wind power is to be realised and these problems revolve around the need to capture energy at a cost per kWh which is competitive with other sources. This depends upon the longevity of the wind turbines which make up offshore wind farms. Their availability, reliability and the efficacy and cost-effectiveness of the maintenance needed to achieve that availability, are essential to improve offshore wind life-cycle costs and the future of this emerging industry. This book intends to address these issues head-on and demonstrate clearly to manufacturers, developers and operators the facts and figures of wind turbine operation and maintenance in the inclement offshore environment, recommending how maintenance should be done to achieve low life-cycle costs.