A STUDY ON EVALUATION OF SEAKEEPING PERFORMANCE FOR PASSENGER SHIPS (3RD REPORT); MEASUREMENTS OF VOMITING RATION IN THE MIDDLE- TERM VOYAGE

The authors measured ship motions and the seasickness ratio of passengers on a cruse ship on a one week voyage. The results show that it is possible to estimate the vomiting ratio with fairly good accuracy using the author's estimation method on the basis of O'Hanson's experimental data. However, when the passengers are exposed to severe ship motions for more than one day, the estimated seasickness ratio after this show an over estimation due to the habituation effect. A decrease function of seasickness ration with time which shows the habituation effect is obtained from the results of the experiment. The seasickness ratio estimated using the function is in fairly good agreement with the results of actual seasickness ratio.