Page 128 - Collision Avoidance Rules Guide

vessel is not taking appropriate action, must obviously take full
account of the possibility that the give-way vessel may also take
simultaneous or subsequent action. The stand-on vessel should avoid
taking action which is likely to conflict with the probable action of
the give-way vessel.
Rule 17(c) requires a power-driven vessel to avoid turning to port
to avoid collision with another power-driven vessel crossing from her
own port side. In such a situation the give-way vessel is required to
avoid crossing ahead and is likely to turn to starboard. An alteration
of course to port may also be dangerous for any stand-on vessel,
including a hampered vessel, sailing vessel or vessel being over-
taken, which has a give-way vessel approaching from the port side.
Rule 8(e) requires a vessel to slacken her speed if necessary to
avoid collision. A reduction of speed made by the stand-on vessel
would make it more difficult for the give-way vessel to cross astern,
which is her most likely method of keeping out of the way. An
increase of speed might even be appropriate in certain circumstances,
particularly in association with helm action, but any alteration of
speed should be substantial and a vessel is unlikely to be proceeding
at reduced speed if the Rules of Section I1 apply. A change of speed
is usually slow to take effect and will be less readily apparent to the
other vessel than helm action.
An alteration of course away from the direction of the other vessel
will usually be the safest manaeuvre, if it is made in sufficient time.
Such a maneuvre could hardly contribute to a collision, even if made
too early, provided it has been established that the bearing is not, in
fact, closing on the bow. Turning away from the other vessel in a
crossing situation will, at least, slow down the rate of approach. If the
give-way vessel is approaching from less than about 60" on the bow
the best action may be to turn away until the other vessel is approxi-
mately abeam, but if the give-way vessel is overtdung or approaching
from near the beam an alteration on to a parallel or slightly diverging
course would probably be the safest action (see also pages 229-32).
Although turning away from the give-way vessel may be the safest
form of avoiding action the presence of other vessels, the proximity
of navigational hazards and other factors must obviously be taken
into account in deciding how to manceuvre. If a hampered vessel
takes action to avoid a give-way vessel approaching from fine on the
starboard bow, which fails to keep out of the way, it may be safer to
make a substantial turn to starboard. The give-way vessel is not

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