ABSTRACT
In general, a feature of good navigation control is that a passage is planned in such a way that, except in the case of unforeseen circumstances, the critical phases of navigation will arise at a time which has been substantially anticipated. By contrast, the need to take action to avoid collision may occur at any stage of the passage and cannot be anticipated except in the most general terms of known areas of high traffic density. Any action or procedure associated with collision avoidance must be based on compliance with the International Regulations for Preventing Collisions at Sea (see also Section 11.24). This text is based on the 1972 Regulations as amended to the 1989 Amendment that came into force on 19 April 1991, and is particularly concerned with the conduct of vessels as governed by the Steering and Sailing Rules (part B of the regulations). The titles of these rules are listed in Section 22.3.1. While part B, section I applies to all conditions of visibility, Section II applies only to vessels in sight of one another, and section III applies to vessels in restricted visibility. It is thus expedient to consider clear visibility and restricted visibility separately.
