We evaluated Transdermal Scopolamine related to the time of application prior to the onset of motion. In this study 44 subjects participated. The first group applied the transdermal disc within 4 h and the second group 8 h or more prior to the onset of motion. We observed a significant decrease in the incidence and the degree of motion sickness for the group with at least 8 h of scopolamine application prior to sea travel. Therefore, the transdermal scopolamine system should be applied at least 8 h before potentially disturbing motion to provide adequate prophylaxis against motion sickness. We found no significant difference in motion sickness susceptibility between men and women, in contrast to earlier reports.