THE REGULATIONS FOB PREVENTING COLLISIONS AT SEA 207
collision, and does not apply to two vessels which must, if both
keep on their respective courses, pass clear of each other.
The only cases to which it does apply are when each of two
„ vessels is end on, or nearly end on, to the other; in other words,
to cases in which, by day, each vessel sees the masts of the other
in a line, or nearly in a line, with her own; and, by night, to cases
in which each vessel is in such a position as to see both the side-
lights of the other.
It does not apply, by day, to cases in which a vessel sees
another ahead crossing her own course; or by night to cases where
the red light of one vessel is opposed to the red light of the other,
or where the green light of one vessel is opposed to the green
light of the other, or where a red light without a green light, or a
green light without a red light, is seen ahead, or where both
green and red lights are seen anywhere but ahead.
Two Steam Vessels Crossing.
ART. 19.—When two steam vessels are crossing, so as to involve
risk of collision, the vessel which has the other on her own starboard
gide shall keep out of the way of the other.
Steam Vessel and Sailing Vessel.
ART. 20.—When a steam vessel and a sailing vessel are proceeding
in such directions as to involve risk of collision, the steam vessel shall
keep out of the way of the sailing vessel."
Course and Speed.
ART. 21.—Where by any of these Bides one of two vessels is to keep
out of the way, the other shall keep her course and speed.
NOTE.—When, in consequence of thick weather or other causes,
such vessel finds herself so close that collision cannot be avoided by
the action of the giving-way vessel alone, she also shall take such action
as will best aid to avert collision. (See Articles 27 and 29.)
Avoid Crossing Ahead.
ART. 22.—Every vessel which is directed by these Rules to keep
out of the way of another vessel shall, if the circumstances of the case
admit, avoid crossing ahead of the other,