Navigational instruments have significantly developed and these improvements have contributed the improvement on ship safety. However, the complexity of the use of the navigational instruments could cause more long-term familiarization for officers, and the question raised whether the utility of these equipment is actually comfortable to “end users” (officers in charge of navigation watch). Furthermore, the complex and numerous functions of the equipment may cause near misses on the navigational watch personnel. Therefore, the authors conducted the questionnaire survey on usability of navigational instruments on board to seafarers who engaged international voyage and domestic voyage. The questionnaire distributed to seafarers asking their experiences on near-miss cases caused by navigational instruments on board. The corrected near-miss cases analyzed with “correspondence analysis” to find the correlation between the seafarers’ individual factors (job title, onboard experience, voyage area) and the navigational instruments factors (function, operation, visual, etc.). There are some findings from the analysis such as 1) Radar, ECDIS, MF/HF radio installation, VHF radio telephone, AIS and Autopilot are most frequently lead near-miss cases, 2) most frequent causes were relate to “functional limitation” and “operational difficulties” and 3) individual factors not influence the causes. These findings are important factors to be considered to operate the navigational instruments. Furthermore, these findings could contribute the future discussions on development of navigational instruments especially in terms of usability at international level.
The development of navigational instruments is remarkable in recent years, and the number of very convenient equipment is increasing. However, it is increasing at the same time a questionable function as to whether it is a function for convenience for the user. The factors by conducting a questionnaire survey on navigational instruments to users were analyzed and identified.