Page 211 - NAVAL SCIENCE 3 TEXTBOOK

RULES OF THE ROAD AND l\I ANE UVERING BOARD 217

a
shorCblast: TOOT ~
~ 1 ONbll
prolonged: T-O-O-T
~ + 6~ CONDS-loi
long: T-O-O-T
~ B 10 ,eCoND' '1

f

Summary of inland rules whistle signals. A-Lengths/duration of whistle signals. B-Crossing situation. Stand-on vessel is on starboard hand (to
the right) of give-way vessel. Stand-on vessel must maintain course and speed; give-way vessel must maneuver, slow, or stop to allow stand-on
vessel to pass ahead. C-Meeting head-on. Both vessels must give way. Vessels exchange single short blasts and maneuver to pass port to port.
O-Meeting situation, but clearly safely separated, allowing for starboard to starboard passage with no maneuvering. Vessels exchange two short
blasts. E-Crossing situation. Stand-on vessel allowed to pass ahead after exchange of one short blast. F~Overtaking Situation, danger to port.
Overtaking vessel proposes overtaking to port with two short blasts, stand-on vessel replies 'Nith five or more short blasts, indicating to give-way
vessel that it may not pass to port because of danger in that direction.

Meeting Situation the appropriate action signals when maneuvering back onto their
original courses, but these signals are commonly omitted, since the
Tn a meeting situation, both vessels arc give~way. In all waters,
danger of collision has passed.
power vessels meeting head-to-head or nearly so are required to
In a meeting situation in international waters in which the
pass port to port. To do so, both vessels must alter course to star-
vessels are not head-on, where no course change is necessary for
board. International rules authorize ani}' a port~to-port pass-
safe passage, no whistle signals are made. Both ships will main-
ing and are silent on a starboard-to~starboard passing. Therefore,
tain course and speed and pass clear. However, the inland rules for
it is implied that a starboard-to-starboard passing is proper under
the same situation require that if vessels arc to pass port-to-port,
international rules only when there is no risk of collision, and no
regardless of whether or not a course change is required, the one~
maneuvering is required. In U.S. inland waters, starboard~to-star~
short -blast signal must be exchanged. If they are going to pass star~
board passing is authorized only if the vessels are not meeting head~
board to starboard, whether or not change of course is required,
to-head and safe passage is assured without any maneuvering.
the two-short-blast signal must be exchanged.
In a port~to-port meeting situation in inland waters, one ves-
Under both sets of rules, starboard-to-starboard passages are
sel gives one short blast on its whistle, telling the other vessel that
discouraged, since misunderstandings can easily lead to a collision.
it intends to come right to make the passage. After the other ves-
There is another old nautical saying that warns: "Two short blasts
sel has answered with a single short blast, indicating understand-
are the first two notes of the collision waltz."
ing and agreement, both vessels turn smartly to the right. The turn
should be large enough to clearly show the action to the oncoming
Crossing Situation
vessel (normally from 5 to 10 degrees in a channel, and about 15
degrees in open waters). Under inland rules, after agreement has A crossillg situatioll on the water is analogous to a four-way
been reached and the turns have been executed, no further sound stop situation on land. In both sets of rules, the power vessel hav-
signals are required during maneuvering to make a safe passage, or ing the other to starboard is the give-way vessel. The vessel to star-
to return to the original courses. board is the stand~on vessel and must maintain course and speed.
In international waters, each ship sounds one short blast as The give~way vessel is required to maneuver if necessary to avoid
thc}' arc executing the right turn. The vessels may choose to sound crossing ahead of the stand~on vessel. This may mean reducing