The International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW) code of the International Maritime Organization (IMO) describes the functions that seafarers must execute in order to realize safe ship navigation. However, the description used to explain these functions implies that the same techniques are necessary in different navigational situations. Thus, there are overlaps in the techniques required of seafarers in different navigational situations. However, as explained earlier, the descriptions of the vital techniques are unclear.