Abstract
The study discusses the influences of different sources of wave statistical data, which were based on visual observations of ocean wave, on long-term predictions of ship responses with special emphasis given to wave data quality. It makes their tendency clearly with the quantification of wave data statistical characteristics. The influences of wave data accumulation on ship responses are also considered by a proposed simple combination methodology of Yamanouchi, Takaishi, and Watanabe's wave data, which presented with some differences in data format. Being compared with reference to the corrected GWS wave data, it shows that it is possible to obtain good estimates of long-term predictions of ship responses by observations accumulations. And it also shows that the quality of wave statistical data is mainly dominated by their collection period, collecting method and so on. A numerical example of the effect of different wave statistical data and the accumulated data for long-term prediction of ship bow vertical relative displacement based on some special sea areas is given.
