Page 181 - NAVAL SCIENCE 3 TEXTBOOK

HASIC SEA:-'IA NSI!IP 187

ably easier than maneuvering a single-screw boat. You need 110t
worry about the separate forces or their combined effect; think of
it as a lever with a force (screw) at each end and the load (boat)
in the middle. Thus, rOll can readily see how much more quickly
a particular maneuver may be accomplished by using the correct
propeller combinations along with the appropriate rudder angle.
for example, to turn your bo,1t 180 dcgrecs to starboard from a
dead stop, use right full rudder, port enginc <lhe,ld, and starboard
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Current engine astern. The boat will make the turn in little more than its
•
own length, whereas a single-screw boat would require consider-
View 1
ably l110re space to complete the same turn. It is also much easier
to get into a short berth or other conn ned space with a twin-pro-
• peller boat .
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Almost all the maneuvers required of a boat can be accolll-
plished by varying the direction and speed of the engines and with-
out using the rudders. An experienced coxswain also can maintain
a fair course by varying the number of turns of the propellers.
Current
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View 2
Boat Etiquette
B
In the Navy the observance of proper boat etiquette is second
A diagram of a starboard-side-to landing in a current using a spring in importance only to safety aspects of boat handling when it
line.
comes to judging the competence of ,1 boat's coxswain and crew.
130at etiquette is concerned with customs, honors, ,mel ceremo-
Starboard-side-to Landing. I\'faking a starboard-side-to landing nies observed by the boat coxswain and crew. J\·10st of these are
is a bit morc difl1cutt than a landing to port. The angle of approach traditions that have been passed along through the years since the
always should clpproximatc that of a port-side-to landing. Speed, founding of our Navy over two hundred years ago.
however, should be slower to avoid having to back down fast to kill The customs that have been established promote the smooth
headway. with the resultant swing of the stern to port. A spring line loading of passengers, help govern boat traffic, and expedite the
should be used when working the stern in alongside the pier. Get movement of boats at gangways and piers. Proper boat etiquette
the line over, use hard left rudder, and kick ahead. is a sign of good seamanship. It also makes a lasting impression on
If YOll C<111110t use a spring line (as when approaching <l gang- all who observe it. Clean boats and sharp, courteollS crews draw
way), time your turn so that, when alongside the spot where you t~l\'orable comments.
intend to swing, your bow is swinging out and your stern is swing- The following few rules of boat etiquette, established by cus-
ing ill. \,"hen it looks as though the stern will make contact, back tOIll and regulations, should serve as a guide to proper conduct
down; as you lose way, shift to hard right rudder. when in boats. Passengers in a boat should observe them closely,
Making use of the current. If there is a ti:lirly strong current from and insist that others do likewise.
'lhead, get the bow line to the pier and the current will bring the
boat alongside. If the current is from aft, the same result can be Rendering Honors
achieved by putting over a stern line first. Care IllUSt be taken dur-
Hand salutes are rendered to boats carrying officers and offi-
ing the approach, because a following current decreases rudder
cials in much the same way as salutes would be made when pass-
efficiency, and steering may be slightly erratic
ing such individuals while walking on land. Junior boats salute the
senior first, and the senior returns the salute. 1t is not the size or
Twin-Screw Boats type of boat, but the rank of the officer aboard that determines a
boat's seniority. Thus, a small boat carrying a commill1der is senior
On twin-screw boats, the st<lrbo<lrd screw is right-handed and the
to a large boat carrying a lieutenant. Usually it is possible to tell by
port screw is left-handed. The lateral (sidewise) forces produced the officer's uniform or by the flilg flown which boat is senior. In
by one screw cancel those of the other when both are going ahead cases of doubt, however, it is best to go ahead and salute.
or astern. \"'hen one is going ahead and the other is going astern,
Boat salutes are rendered bya boat's coxswain and by the senior
however, the forces complement each other, and the effect is dOLl-
officer embarked. The enginE' of the junior boat should be idled
bled. For this reason, maneuvering a twin-screw boat is consider-