The study aims to determine mean annual wave heights and wind speeds in the Adriatic Sea. The Adriatic serves as a shipping route towards central Europe and a food and energy source for surrounding countries. Wave and wind climate information can serve as basis for design, research and policy making regarding ship safety and operability, potential renewable energy exploitation, design of off-shore installation etc. Mean annual wave height and wind speed values have been statically derived based on 43,274 ship sea state observations reported by the Hydrographical Institute of Republic of Croatia. This data has been digitalized and processed resulting in mean annual observed wave heights and corresponding wind speed values. Calm sea and no wind time percent periods have been calculated and wind-speedto-wave-height correlations presented. The obtained results are discussed for accuracy, significant effects are listed and future work guidelines are given.

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After facing some criticism regarding assumptions contained in IACS Rec. No. 34 Rev 1 (2001), efforts have been put in by IACS members resulting in a new revision of this document, which provides a procedure for computation of the long-term extreme wave loads on ocean-going ships. The main changes include a new scatter diagram, modification of the wave spectral model and energy spreading function, as well as probability level of design load. Preliminary, the reduction of extreme loads from 10% to 30%, depending on the vessel and response type, is estimated. As this reduction could have serious implications for ship structural design, the present research aims to further investigate consequences on the most important load component, i.e., vertical wave bending moment (VWBM) at midship. Transfer functions of VWBM are calculated using closed-form expressions, which are convenient for comparative studies where many computations are required. Ships of different types and sizes are subjected to the long-term VWBM analysis comparing extreme values based on the procedures proposed in Rev 1 and Rev 2. Although this study is not intended to provide extreme VWBM in absolute terms, the comparison with IACS UR 11 is nevertheless presented as a reference. It is found that Rev 2 long-term VWBMs never exceed corresponding IACS Rule values, which can’t be stated for Rev 1. Results also indicate that differences in scatter diagrams between Rev 1 and Rev 2 could explain a large decrease in the extreme VWBM.