Page 142 - Collision Avoidance Rules Guide

Rules hovercraft and hydrofoils, are not classed as seaplanes, even
when operating in the non-displacement mode, but are to be consid-
ered as power-driven vessels. It was decided that they should not be
required to keep out of the way of all other vessels as air-cushion ves-
sels are not always capable of achieving very high speeds. However,
it might be considered to be an act of good seamanship, in compli-
ance with Rule 2(a), for hovercraft and hydrofoils proceeding at high
speed to take early action to keep well clear of all shipping.
Air-cushion vessels operating in the non-displacement mode are
very susceptible to wind effects. Such vessels may have a drift angle
of as much as 45", so their navigation lights may give a false indica-
tion of the direction of travel. It is mainly for this reason that all air-
cushion vessels are required by Rule 23(b) to exhibit an all-round
flashing yellow light in addition to the lights prescribed for power-
driven vessels underway.

WIG crnft
Paragraph (f) was added to Rule 18 by the 22nd Assembly of IMO in
2001. This paragraph refers to WIG craft, which are required when
taking-off, landing and in flight near the surface to keep well clear of
all other vessels and avoid impeding their navigation. This require-
ment also applies to a WIG craft taking-off, landing or in flight near
the surface when there is risk of collision with another vessel. When
operating on the water surface, not taking-off or landing, a WIG craft
must comply with the Rules as a power-driven vessel.

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