Mental Workload of Ship’s Navigator – A Few Comments on Heart Rate Variability during Navigational Watch Keeping – Koji Murai 1 , Yuji Hayashi 1 , Noriko Nagata 2 , and Seiji Inokuchi 3 1 Kobe University of Mercantile Marine Kobe, Hyogo 658-0022, Japan {murai,hayashi}@cc.kshosen.ac.jp 2 Kwansei Gakuin University Sanda, Hyogo 669-1337, Japan nagata@ksc.kwansei.ac.jp 3 Hiroshima International University Kurose, Hiroshima 724-0695, Japan inokuchi@he.hirokoku-u.ac.jp Abstract. A navigator efforts to handle the ship for safe navigation by judging navigational information on own ship’s condition, targets and current-wind effect, and he/she has the responsibility of human lives and economical values under the judgment. The navigator keeps a men- tal workload during the navigational watch keeping. Therefore, we need the development of a support system to reduce the mental workload with human-system cooperation based on navigator’s KANSEI, and we must research on an index to asessment of a mental workload for the first step. The purpose of this paper is to find charac- teristics of navigator’s mental workload with heart rate variability (R-R interval). The experiment carry out for six kinds of sea area in Japan, and the subject is chief officer of a training ship in Kobe University of Mercantile Marine. 1 Introduction A navigator gets navigational information from own ship’s condition and her navigational environment through five senses, and he/she keeps to handle the ship for safe navigation to recognize and analysis it. For modern navigation, a navigator is supported by the navigational instru- ment, and he/she has obtained the convenience and human ability promotion from human-systems cooperation. Now, we mainly request the system draws the ability of a navigator. In short, it put navigator’s KANSEI to practical use, and its system guide naturally him/her to safe navigation. Here, human KANSEI is an individual sense, and its ability is not always achieved by the experience. In this paper, we define KANSEI is a sense including perception, recognition and awareness under conscious and unconscious level. Also, it is said that there are public’s, artist’s and professional’s KANSEI in the type 1-3 . V. Palade, R.J. Howlett, and L.C. Jain (Eds.): KES 2003, LNAI 2774, pp. 897–903, 2003. c  Springer-Verlag Berlin Heidelberg 2003