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.
When the IRPCAS right-of-way rules replace the rules of
Part 2, they effectively prohibit a right-of-way boat from
changing course towards the boat obligated to keep clear
when she is close to that boat.
Facts
The notice of race for an overnight race had, between sundown and sunrise,
replaced the rules of Part 2 with the IRPCAS right-of-way rules. At about
0030, L and W were running on starboard tack on parallel courses about two
hull lengths apart. W was clear astern of L and on a track to windward of
L’s track, and was steadily closing up on L. 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 stern light of that vessel but neither of her
sidelights.’ n 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, L’s appeal is dismissed and the protest committee’s decision to
penalize her is upheld.
CAN 1976/32