Page 27 - Collision Avoidance Rules Guide

Special circumstances and immediate danger
This Rule does not give any vessel the right to take action contrary to
the Regulations whenever it is considered to be advantageous to do so.
A departure is only permitted when there are special circumstances
and there is immediate danger. Both conditions must apply. The depar-
ture must be of such a nature as to avoid the danger which threatens.

Squadrons or convoys
The Mariners’ Handbook draws the attention of mariners to the dangers
which may be caused by single vessels attempting to pass ahead of, or
through a squadron of warships or merchant vessels in convoy. Single
vessels are advised to take early measures to keep out of the way, and
the vessels in the squadron or convoy are warned to keep a careful
watch and be ready to take such action as will best aid to avert collision.
Mariners are expected to take into account the cautions and
recommendations given in Notices to Mariners and other official
publications but if a vessel in a formation or convoy is approached by
a single vessel so as to involve risk of collision the Steering and
Sailing Rules must be complied with.
Action taken in accordance with the advice to avoid a squadron or
convoy on the port bow would not be a departure from the Rules
if executed at long range before risk of collision begins to apply
(see pages 37-38).

Duty to depart ifnecessary
If a departure from the Rules is necessary to avoid immediate danger
a vessel would not only be justified in departing from them but may
be expected to do so.

Tasmania-City of Corinth
It is provided by Rule . . . that, in obeying and construing the Rules,
due regard shall be had to any special circumstances which may render
a departure from them necessary in order to avoid immediate danger.
As soon then as it was, or ought, to a master of reasonable skill and
prudence, to have been obvious that to keep his course would involve imme-
diate danger, it was no longer the duty of the master of the Tasmania to
adhere to the. . . Rule. He was not only justified in departing from it, but
8