Since seasickness is a major problem for seagoing personnel a simple solution can be to predict in advance who might be less susceptible to this disorder. We in the Israeli Navy conducted very extensive studies and we found very effective method to predict it.
This paper describes our efforts to develop a personnel selection procedure based on a neurogenic laboratory test (NT).
The first study employed concurrent validation as the basic methodology. Fifty-five sailors with at least 3 months experience at sea rated their seasickness susceptibility using a self rating Likert type scale. They were then exposed to the 6 min NT.
This test was conducted on a rotating chair and consisted of cross-coupled angular accelerations and sudden stops. The severity of motion sickness provoked by the NT was measured using a motion sickness symptom questionnaire. Significant positive correlations were found between sea sickness susceptibility and the severity of motion sickness provoked by the NT. The second study assessed the test’s predictive validity.
Subjects were 67 males about to commence their naval service, who were tested with the NT before their actual exposure to sea conditions. 48 hours after the test, they were exposed to rough seas and were asked to perform the daily activities of crewman. Trained observers monitored their seasickness and its effect on performance, and rated these parameters on a 5 point scale. A year later. these parameters were again evaluated by the vessels commanders. Significant positive correlations were found between NT and both seasickness susceptibility and decrements in performance at sea as evaluated on both occasions.
Prediction by the NT of short and long-term seasickness susceptibility and level of performance suggests that this test might be useful as part of a naval selection procedure