Page 29 - Collision Avoidance Rules Guide

(ii) a vessel engaged in dredging, surveying or underwater
operations;
(iii) a vessel engaged in replenishment or transferring
persons, provisions or cargo while underway;
(iv) a vessel engaged in the launching or recovery of aircraft;
(v) a vessel engaged in mine clearance operations;
(vi) a vessel engaged in a towing operation such as severely
restricts the towing vessel and her tow in their ability to
deviate from their course.
The term ‘vessel constrained by her draught’ means a
power-driven vessel which because of her draught in relation
to the available depth and width of navigable water is
severely restricted in her ability to deviate from the course
she is following.

The word ‘underway’ means that a vessel is not at anchor,
or made fast to the shore, or aground.
The words ‘length’ and ‘breadth’ of a vessel mean her length
overall and greatest breadth.
Vessels shall be deemed to be in sight of one another only
when one can be observed visually from the other.
The term ‘restricted visibility’ means any condition in which
visibility is restricted by fog, mist, falling snow, heavy rain-
storms, sandstorms or any other similar causes.
(m) The term ‘wing-in-ground (WIG) craft’ means a multi-
modal craft which, in its main operational mode, flies in close
proximity to the surface by utilizing surface-effect action.

COMMENT:
The definitions given in Rule 3 are those which have general appli-
cations throughout the Rules. Definitions concerning lights and
whistle signals are given in sections C and D (Rules 21 and 32).
(a) This paragraph replaces Rule l(c)(i) of the 1960 Rules. Non-
displacement craft, WIG craft and seaplanes are now to be considered
as vessels, whereas seaplanes were given separate treatment throughout
the 1960 Rules.
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