Abstract
Tests were conducted on board the training ship of the Ministry of Transportation on the Miyazaki-Amami Islands and Amami Islands-Tokyo routes. The tests consisted of questionnaires and correlations between the degree of acceleration and the severity of seasickness.
The subjects were 124 students of the Merchant Marine Schools of Tokyo and Kobe.
1. A family history of susceptibility to seasickness and autonomic nervous system symptoms such as urticaria and discomfort in elavators were found to be predisposing factors in seasickness.Bad health, fear of vehicles and standing at work on the ship were considerered to be susceptibility factors of seasickness.
2. Stimulation of the Otoliths by linear acceleration was found to be the direct trigger of seasickness. The larger the acceleration, the worse was the seasickness.
3. Seasickness is thought to be due to the degree of acceleration and irritability of the vestibular labyrinths and brain stem and the degree of suppression by the cerebrum and cerebelium in addition to the various susceptibility factors.Other factors, except for the degree of acceleration, are probably related to personal predis-posing factors.
