171-DG-2
Page 1 of 2
©
Copyright Lapware 2002
USCG 171 Book 2
STEPS
You have determined the maneuvering characteristics of your vessel by taking
the radar ranges and bearings of an isolated light while making a turn. The results
are as listed. Based on this data what is the transfer for a turn of 30°?
Reference: KNIGHT; 33 CFR 164.35 (g) (1)-(7)
Position
Heading
Bearing
Bearing
Range
Number
True (T)
True (T)
True (T)
(Yards)
A
333°
315°
135°
2,125 * On Initial Heading 333°T
1
333°
310°
130°
1,650 * Left Full Rudder Ordered
2
327°
307°
127°
1,475
3
310°
303°
123°
1,250
4
278°
302°
122°
1,050
5
268°
305°
125°
900
6
236°
318°
138°
750
7
196°
337°
157°
800
8
157°
344°
164°
1,100
9
113°
340°
160°
1,350
10
079°
332°
152°
1,525
11
050°
324°
144°
1,575
12
022°
318°
138°
1,550
13
343°
308°
128°
1,400 * Rudder Amidships
14
333°
302°
122°
1,175 * Steady On Heading 333°T
From Ship From Light
To Light
To Ship
Getting Started
1.
Construct the Turning Circle utilizing a maneuvering board (DMA 5090)
2.
Plot the position of the isolated light described in the stem of the problem in the
center of the maneuvering board.
3.
Use a 2:1 scale to plot the range and bearing which forms the path of the vessel
through the turn.
4.
Use the
Ranges
in yards and
True Bearing From the Light to the Ship
(Reciprocal of the bearing provided in Diagram D035DG: True Bearing From the
Ship To the Light - 180° = True Bearing from the Light To the Ship). This scribes
the path of the vessel for a left turn. Number each reference point on the plot. The
initial position can be labeled as "A" (Bearing 333°T at a range of 2,125 yards).
5.
The turn commences when "Left Full Rudder" is ordered at this time the vessel is
on a True Heading of 333°T with the isolated light bearing 310°T at a range of
DECK GENERAL
Maneuvering Diagram