On July 15, 1977, at 12 00 hours zone time, the International Regulations for Preventing Collisions at Sea, 1972, came into force. The Regulations are presented in a logical order. They are divided into five parts, A to E, followed by four annexes. Part A deals with the application of the Rules, responsibility to obey them and definitions which apply to all the Rules. Part B contains the Steering and Sailing Rules. The technical details on lights and shapes are dealt with in Part C, while Part D is devoted to sound and light signals. Part E deals with exemptions.

Annex I on “Positioning and technical details of lights and shapes” contains details on the placing of lights. It also contains technical details on the navigational lights to ensure uniform colour intensities. Annex II on “Additional signals for fishing vessels fishing in close proximity” aims at the standardisation of the signals. Annex III is entitled “Technical details of sound appliances”, while Annex IV is on “Distress signals”.

Radical changes have been brought about by the Rules. It is not the intention here to deal with these changes. This paper is limited to a study of Rule 15 on “Crossing Situation”.

It must be noted that some of the cases decided under the 1960 Rules are not valid under the present Rules. Reference in this paper is made only to the decisions which are not affected by the amendments.

Another important remark concerns the non-party States to the 1972 Rules. States having 35 % of the world tonnage are not yet party to the 1972 Rules, but they may be party to the 1960 Rules. This would present a real difficulty. The crucial point seems to be whether it is reasonable for those on board a vessel to assume that the other vessel is party to the new Rules, or whether they should have anticipated the possibility that the other vessel is not party to the new Rules and bound by the old ones.

To put the problem in another way, the fact that the Collision Regulations, 1960, would be allowed to remain effective after July 15, 1977, would increase the hazards in sea traffic for those ships which are about to enter the indefinable borderline between the high seas and the territorial waters of a non-party State. Added to this, ships may be forced to equip themselves with the special lights and signals that would meet the requirements of both the 1960 and 1972 Collision Regulations.

Turning now to Rule 15, it states:—

Thus, it is clear that in a crossing situation, the duty of the ship, having the other on her starboard side, is to keep clear of the other ship and, if practicable, to avoid crossing ahead of her. She would keep clear without crossing ahead in three ways