1996 Volume 94 Pages 273-279
In order to study on the safety of fishing operation on the small fishing boat for raising scallops in Funka bay in a severe winter, the authors have measured the wave height on the fishing ground at stormy weather, and the seakeeping qualities. In this paper, the safety is discussed from the stand-points of the wave height and the rolling angle of the fishing boat. We got the following results ; (1) The distribution of power spectra of the movement of the sea surface in the coastal area, whose sea condition is dangerous for fishing operation, exhibits two strong powers, because the movement is consisted of the short periodical wave generated from the periodic wind blowing from the direction of north-west and the long periodical swell transmitted from the Pacific Ocean. (2) The distribution of the wave height in the above condition can be approximated well by using the distribution function of the Beta distribution, although the fitting of distribution functions of the Rayleigh distribution and the Log-Normal distribution are not successful. (3) The results of the fitting to the estimated distribution for the rolling angle of the fishing boats, by using several distribution functions, suggested that the distribution function of the Beta distribution can estimate well the probabillity concerning the safety, although the distribution function of the Rayleigh distribution underestimate it.
