For the purpose of these Rules and this Chapter [Inld], except where the context otherwise requires:
(a) The word "vessel" includes every description of watercraft, including non-displacement craft, WIG craft [Intl], and seaplanes, used or capable of being used as a means of transportation on water.
(b) The term "power-driven vessel" means any vessel propelled by machinery.
(c) The term "sailing vessel" means any vessel under sail provided that propelling machinery, if fitted, is not being used.
(d) The term "vessel engaged in fishing" means any vessel fishing with nets, lines, trawls, or other fishing apparatus which restrict maneuverability, but does not include a vessel fishing with trolling lines or other fishing apparatus which do not restrict maneuverability.
(e) The term "seaplane" includes any aircraft designed to maneuver on the water.
(f) The term "vessel not under command" means a vessel which through some exceptional circumstance is unable to maneuver as required by these Rules and is therefore unable to keep out of the way of another vessel.
(g) The term "vessel restricted in her ability to maneuver" means a vessel which from the nature of her work is restricted in her ability to maneuver as required by these Rules and is therefore unable to keep out of the way of another vessel. The term [Int] "vessels restricted in their ability to maneuver" shall [Int] include but not be limited to:
A vessel engaged in laying, servicing, or picking up a navigational 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.
(h) The term "vessel constrained by her draft" means a power-driven vessel which because of her draft 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. [Int]
(i/h) The word "underway" means that a vessel is not at anchor, or made fast to the shore, or aground.
(j/i) The words "length" and "breadth" of a vessel mean her length overall and greatest breadth.
(k/j) Vessels shall be deemed to be in sight of one another only when one can be observed visually from the other.
(l/k) 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.
(l) "Western Rivers" means the Mississippi River, its tributaries, South Pass, and Southwest Pass, to the navigational demarcation lines dividing the high seas from harbors, rivers and other inland waters of the United States, and the Port Allen-Morgan City Alternate Route, and that part of the Atchafalaya River above its junction with the Port Allen-Morgan City Alternate Route including the Old River and the Red River; [Inld]
(m) The term "Wing-In-Ground (WIG) craft" means a multimodal craft which, in its main operational mode, flies in close proximity to the surface by utilizing surface-effect action. [Intl]]
(m) "Great Lakes" means the Great Lakes and their connecting tribuatary waters including the Calumet River as far as the Thomas J. O'Brien Lock and Controlling Waters (between mile 326 and 327), the Chicago River as far as the east side of the Ashland Avenue Bridge (between mile 321 and 322), and the Saint Lawrence River as far east as the lower exit of Saint Lambert Lock; [Inld]
(n) "Secretary" means the Secretary of the department in which the Coast Guard is operating; [Inld]
(o) "Inland Waters" means the navigable waters of the United States shoreward of the navigational demarcation lines dividing the high seas from harbors, rivers and other inland waters of the United States and the waters of the Great Lakes on the United States side of the International Boundary; [Inld]
(p) "Inland Rules" or "Rules" mean the Inland Navigational Rules and the annexes thereto, which govern the conduct of vessels and specify the lights, shapes, and sound signals that apply on inland waters; and [Inld]
(q) "International Regulations" means the International Regulations for Preventing Collisions as Sea, 1972, including annexes currently in force for the United States. [Inld]