Abstract
Using Ergonomics method, the writer attempt to examine the dynamic aspect of mental Strain of Navigators during sea navigation watch. The results are as follows: 1. Physical and mental reaction of Navigators are caused by following stimuli, for example, searching L't Ho, . alternation course and existence of other vessels. 2. Pattern of P.G.R. shows extreme difference between open sea and narrow channel, skilled and unskilled, approaching pier and sea going. 3. C.T.G. rate, in good triffic condition, shows regular fluctuation, but in traffic convergency or risk of collision shows acceleration.
