CASE 38

International Regulations for Preventing Collisions at Sea

The International Regulations for Preventing Collisions at Sea (IRPCAS) are intended to ensure the safety of vessels at sea by precluding situations that might lead to collisions. They effectively prohibit a right-of-way boat from changing course when she is close to a boat obligated to keep clear.

Summary of the Facts
At about 0030, L and W were running on starboard tack on parallel courses about two hull lengths apart. W was to windward and clear astern of L and steadily closing up on her. The IRPCAS had been made applicable by the sailing instructions. L changed course to starboard, forcing W to respond in order to avoid a collision. W protested L on the grounds that ‘luffing was forbidden at night’. The protest committee upheld the protest under the IRPCAS, Part B, Section II, Rule 17. L appealed on the grounds that the protest committee had misapplied the relevant IRPCAS rules.

Decision
IRPCAS Rule 13 (a) states that ‘any vessel overtaking any other shall keep out of the way of the vessel being overtaken’, and Rule 13 (b) states, ‘A vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft her beam, that is, in such a position with reference to the vessel she is overtaking, that at night she would be able to see only the sternlight of that vessel but neither of her sidelights’. In the above case W was the overtaking vessel. Rule 13 (d) states, ‘Any subsequent alteration of the bearing between the two vessels shall not . . . relieve [the overtaking vessel] of the duty of keeping clear of the overtaken vessel until she is finally past and clear.’

The overtaken vessel, in this case L, has obligations towards the overtaking vessel. These are in Rule 17 which states in part, ‘Where one of two vessels is to keep out of the way, the other shall keep her course and speed’. It is this rule that prohibits the racing manoeuvre known as ‘luffing’ while the boats are so close that L’s luff forces W to change course to avoid contact. Therefore, the appeal is dismissed and the protest committee’s decision to penalize L is upheld.

CYA 1976/32