Page 96 - Collision Avoidance Rules Guide

that it is within the ordinary practice of prudent seamanship and in
keeping with the provisions of Rule 10 of the 1972 Regulations that
a vessel using a traffic lane may make a transfer within a lane from
one side to the other, provided such a transfer is accomplished at as
small an angle to the general direction of traffic flow as is practi-
cable. This point has now been incorporated in the IMO Guidance for
the Uniform Application of Certain Rules of the 1972 Collision
Regulations.
It is also possible that a vessel may only want to cross one traffic
lane and the separation zone or line to join the other traffic lane at as
small an angle to the general direction of traffic flow as practicable.
Such a manaeuvre must be carried out with caution and full aware-
ness of the traffic moving in the scheme. The requirement to cross at
right angles is not limited to a vessel crossing both lanes of a traffic
separation scheme.

Century Dawn-Asian Energy
It was submitted by Mr Teare that on the true construction of Rule lO(c) the
obligation to cross a separation lane as nearly as practicable at a right angle
only applied to vessels crossing both lanes and not to vessels crossing one
lane with a view to joining the other. It was further submitted that under
Rule lO(b)(iii) it was the obligation of Century Dawn to join the eastbound
lane at as small an angle as possible so that she was justified in crossing the
westbound lane at less than a right angle. I do not accept those submissions.
In my judgment, particularly in the light of the advice of the assessors which
I have set out above, the obligation in Rule 1O(c) applies to vessels crossing
any traffic lane whether the purpose of crossing it is to cross the next lane or
to join it. Of course the obligation to cross at a right angle is qualified by the
expression ‘as nearly as practicable’. Moreover, no attempt should be made
to cross either lane in a traffic separation scheme unless it is safe to do so.
(Mr Justice Clarke, 1994)

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