These Rules shall apply to all vessels upon the high seas and in all waters connected therewith navigable by seagoing vessels.
Nothing in these Rules shall interfere with the operation of special rules made by an appropriate authority for roadsteads, harbours, rivers, lakes or inland waterways connected with the high seas and navigable by seagoing vessels. Such special rules shall conform as closely as possible to these Rules.
Nothing in these Rules shall interfere with the operation of any special rules made by the Government of any State with respect to additional station or signal lights, shapes or whistle signals for ships of war and vessels proceeding under convoy, or with respect to additional station or signal lights or shapes for fishing vessels engaged in fishing as a fleet. These additional station or signal lights, shapes or whistle signals shall, so far as possible, be such that they cannot be mistaken for any light, shape or signal authorized elsewhere under these Rules.
Traffic separation schemes may be adopted by the Organization for the purpose of these Rules.
Whenever the Government concerned shall have determined that a vessel of special construction or purpose cannot comply fully with the provisions of any of these Rules with respect to the number, position, range or arc of visibility of lights or shapes, as well as to the disposition and characteristics of sound-signalling appliances, such vessel shall comply with such other provisions in regard to the number, position, range or arc of visibility of lights or shapes, as well as to the disposition and characteristics of sound-signalling appliances, as her Government shall have determined to be the closest possible compliance with these Rules in respect of that vessel.
Nothing in these Rules shall exonerate any vessel, or the owner, master or crew thereof, from the consequences of any neglect to comply with these Rules or of the neglect of any precaution which may be required by the ordinary practice of seamen, or by the special circumstances of the case.
In construing and complying with these Rules due regard shall be had to all dangers of navigation and collision and to any special circumstances, including the limitations of the vessels involved, which may make a departure from these Rules necessary to avoid immediate danger.
For the purpose of these Rules, except where the context otherwise requires:
The word vessel includes every description of water craft, including non-displacement craft and seaplanes, used or capable of being used as a means of transportation on water.
The term power-driven vessel means any vessel propelled by machinery.
The term sailing vessel means any vessel under sail provided that propelling machinery, if fitted, is not being used.
The term vessel engaged in fishing means any vessel fishing with nets, lines, trawls or other fishing apparatus which restrict manoeuvrability, but does not include a vessel fishing with trolling lines or other fishing apparatus which do not restrict manoeuvrability.
The word seaplane includes any aircraft designed to manoeuvre on the water.
The term vessel not under command means a vessel which through some exceptional circumstance is unable to manoeuvre as required by these Rules and is therefore unable to keep out of the way of another vessel.
The term vessel restricted in her ability to manoeuvre means a vessel which from the nature of her work is restricted in her ability to manoeuvre as required by these Rules and is therefore unable to keep out of the way of another vessel. The term vessels restricted in their ability to manoeuvre shall include but not be limited to:
a vessel engaged in laying, servicing or picking up a navigation mark, submarine cable or pipeline;
a vessel engaged in dredging, surveying or underwater operations;
a vessel engaged in replenishment or transferring persons, provisions or cargo while underway;
a vessel engaged in the launching or recovery of aircraft;
a vessel engaged in mine clearance operations;
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 rainstorms, sandstorms or any other similar causes.