Navigation Flashcards
1
Q
When speaking of degrees in giving course or heading, always use
A
three digits
2
Q
Directions on the charts are in both
A
true degrees and magnetic degrees
3
Q
True direction uses the ______ ______ ____ as a reference point.
A
geographic North Pole
4
Q
Magnetic direction uses the ____ ____ ___ as the reference point
A
Magnetic north pole
5
Q
The difference between the true and magnetic direction is called
A
variation
6
Q
Directions steered on the compass are either
A
true degrees or magnetic degrees
7
Q
The direction of vessel, land mass or landmark in a 360 degree circle in reference to the vessel’s bow are
A
relative bearings whereas true and magnetic use true or magnetic north as the reference. For example 000 degrees if “dead ahead” and 090 degrees if off the starboard beam, 180 degrees is directly astern and 270 degrees if off the port beam
8
Q
The sum of there errors ( variation and deviation) that precent a magnetic compass from reading true north are called
A
compass error
9
Q
Variation varies according to
A
geographic location
10
Q
The variation for any geographic location can be dound
A
near the center of the compass rose nearest to the area of operation on the nautical chart of the area
11
Q
Increases in variation may continue for many years, sometimes reaching large values, and then
A
decrease again
12
Q
Determine the mouth of variation
A
Find the compass rose nearest to your location
Locate the variation and annual increase/decrease from the compass rose and the year observed
Subtract the year indicated in the compass rose from the present year
Multiply the number of years difference by the annual increase or decrease and round to the nearest whole degree
Add or subtract the amount of change to the variation printed in the compass rose
13
Q
The magnetic compass error caused by magnetic influences on the vessel is call
A
deviation
14
Q
Sources of compass deviation include
A
Metal objects around the compass
electrical motors and electronic equiment
The vessel itself
15
Q
Deviation is measured in
A
degrees and will be either east or west of what the actual magnetic heading should be
16
Q
The amount of deviation is determined by
A
swinging ship
17
Q
on board a ship, the deviation is recorded on a
A
deviation table and posted near the compass
18
Q
The deviation table lists deviation for every
A
15 degrees of the compass
19
Q
Deviation can also be determined by
A
running a range, which is a line of bearing made by any two fixed landmarks on a nautical chart. Coast Guard navigation ranges which typically mark the center of a channel are excellent for this purpose
20
Q
And aid to navigations is
A
any device external to a vessel or aircraft intended to assist a navigator to ermine position or safe course or to warn of dangers or obstructions to navigations
21
Q
On seacoasts, lateral aids conform to the
A
conventional direction of buoy age, which is clockwise direction around the coastline from north to south on the Atlantic coast and south ton other and then west in the Gulf of Mexico and south ton other on the Pacific Coast
22
Q
Lateral aides found at junctions of navigable channels and often mark wrecks or obstructions
A
Preferred Channel Marks
23
Q
____ _____ ____ band indicates the side of the preferred channel on Preferred Channels Marks usually the “main” channels when entering from seaward.
A
The top color
24
Q
If a Preferred Channel Mark is lighted, the light color will be
A
the same as the color of the top band.
25
Preferred channel buoys may be _____ but not _____.
Letters but not numbered
26
These aid are used to mark fairways, mid-channels, and offshore approach point and have unobstructed water on all side. They can also be used by a vessels operator transiting offshore waters to identify the proximity of intended landfall.
Safe Water Marks
27
Safe water marks may have a _____ topmark
red
28
These aids indicate an isolated danger which may be passed on all sides
Isolated Danger Marks. They are erected on or moored on or near diners and should not be approached closely without special caution.
29
This aide is a Pair of aids to nivation which when lined up Wirth eat other, mark a channel center line.
Ranges or Range Loghts
30
Special Marks (Yellow) are not intended to assist in navigation, but rather to alert the mariner to a special feature or area such as
Spoil areas
Pipelines
Traffic Separation Schemes
Jetties
31
Which marks have orange geometric shapes agains a white backgrou
Information and regulatory marks.
32
The meaning associate with the orange shapes are
Open-face diamond signifies danger
vertical diamond shape having a cross center within indicates vessel are excluded
circular shapes indicated that certain operating restrictions are in effec
33
A watch circle is defined by
mooring lengths and buoys can be expected to move within this circle. Actual watch circles do not coincide with the symbols representing them on charts.
34
Mariners should never rely on
buoys alone to determine positition
35
aids to navigation which are permanently fixed to the earth's surface are
Beacons
36
Beacons include
large lighthouses to small single-pile structures and may be located on land or in the water.
37
Lighted beacons are called
lights
38
unlighted beacons are called
daybeacons
39
beacons exhibit a
day marks. These are color geometric shapes which make an aid to navigation readily visible and identifiable agains background conditions
40
a lighthouse's day make can be
the structure itself.
41
These daymares have no ____ significance
lateral
42
What has a considerable effect on the distance which lights can be seen
The condition of the atmosphere including fog, have, dust, smoke or precipitation
43
What can cause a light to be seen further away than under ordinary circumstances
Atmospheric refraction
44
The glow os a powerful light is called
loom
45
What can reduce the distance at which buoy lights are detected
buoy motion
46
What in general, are used to make shoals or to warn the mariner of other obstructions to navigator or of nearby land
red sectors
47
Only aids with lateral significance have
green or red lights
48
___ lights on aid to navigation mark ports sides of channels and locations of wreck or obstructions that must be passed by keeping these lighted aids to navigation on the port hand of a vessl
Green lights
49
What colored lights are used on aids to navigation marking starboard side of channels and locations of wrecks or obstructions that must be passed by keeping these lighted aids to navigation on the starboard and os a vessel. The same color lights are also used on preferred channel maps where the the preferred channel is to port
Red lights
50
Dhow are light rhythms laterally significant
they aren't
51
Red or green flashing lights less than 30 flashes per might will
make the side of a channel
52
A yellow flashing light indicates
a special mark
53
Preferred channel marks exhibit a
composite grou-flashing (2+1) light rhythm of two flashes followed by a single flash
54
Safe water mark lights she a
white Morse code "A" rhythm (a short flash followed by a long flash)
55
Safe water marks are used to mark
fairways, mid-channels and offshore approach points and have unobstructed water on all sides.
56
Isolated danger mark lights show
a white flashing (2) rhythm (two flashes repeated regularly)
57
A quick flashing light flashes
more than 60 flashes per minute
58
A quick flashing light indicates
a distinct cautionary significance such as sharp turns, sudden channel constrictions, wrecks or obstructions
59
All solid red and solid greenaids to navigation are
numbers
60
red aids to navigation have
even numbers
61
green aids to navigation have
odd numbers
62
the numbers on solid red and solid green aids to navigation increase from
seaward, proceeding in the conventional direction of buoyage
63
Letters will increase in alphabetical order from seaward,
proceeding in the conventional direction of buoy age and are added to numbers as suffixes
64
Preferred channel, safe water, isolated danger, special marks, and information and regulatory aids to navigation may be but not numbered.
lettered, but number numbreed
65
Which buoys and dashboard shapes mark the left side of a channel when proceeding from seaward and are associate with solid green or green and red-banded marks where the top-most band is green
cylindrical buoys (can buoys) and square dayboards
66
mark the ___ buoys and ____ dayboards mark right side of the channel when proceeding from seaward. These aids to navigation are associated with solid red or red and green-banded marks where the topmost band is red.
Conical buoys (nun buoys) and triangular dashboards
67
The Intarcoastal Waterway (ICW) runs parallel to the Atlantic and Gulf coasts from New Jersey to the Mexican border. Aids to navigation marking the ICW display
unique yellow symbols to distinguish them from aids marking other waters. When following the conventional direction of buoyage, yellow triangles indicate aids that should be kept to starboard (right), and those with yellow squares should be kept to port (left).A yellow reflective horizontal strip on a dayboard indicates the aid to navigation marks the Intracoastal Waterway, but it has no lateral significance.
68
Lights and other marine aids to navigation and maintained by or under authority of
the U.S. Coast Guard
69
Lights and other marine aids to navigation, maintained by or under authority of the U.S. Coast Guard and located on waters used by general navigation, are described in
the Light List
70
The Light List is published in
seven volumes, covering all waters of the U.S. and its possessions.
71
The light list includes all
Coast guard aids to navigation used for general navigation such as lights, sound signals buoys, and daybeacons.
72
The light list does not include
Coast Guard mrooring buoys, and some buoys having no lateral significance such as special purpose, anchorage, fish net and dredging .
73
The Light List is published via hardcopy
annually
74
The electronic version of the Light List is updated
weekly
75
Changes to aids to navigation during the year are published in
U.S. Coast Guard Local Notices to Mariners and National Geospatial Intelligence Agency (NGA) Notices to Mariners.
76
A summary of corrections for the Light List, which includes corrections from the dates shown on the title page to the date of availability, is published in
the Local Notice to Mariners and the Notice to Mariners.
77
Names of aids to navigation are printed as follows to help distinguish at a glance the type of aid to navigation listed:
```
Seacoast/Lake coast Lights and Secondary Lights
RACONS
Sound Signals
River, Harbor, and Other Lights
Lighted Buoys
Daybeacons and Unlighted Buoys
```
78
Aids to navigation are numbered by in accordance with their order of appearance in each volume of the Light List. Other numbers and decimal fractions are assigned where newly established aids to navigation are listed between previously numbered aids to navigation.
fives
79
International numbers are assigned to certain aids to navigation in cooperation with t
he International Hydrographic Organization. They consist of an alphabetic character followed by three or four numeric characters.
80
The visibility of a lighted aid to navigation depends upon two factors:
Intensity of the light (candlepower)
| Its height above water
81
With regards to lighted aids geographic range is
the maximum distance at which a light may be seen in perfect visibility by an observer at sea level.
82
With regards to lighted aids, computed range is
the geographic range plus the observer’s distance to the horizon based on the observer’s height of eye.
83
With regards to lighted navigations aids, computed visibility is
the visibility determines for a light using the light's height, nominal ranges and the height of the eye of the observer
84
For a lighted navigational aid, luminous range is
the maximum distance at which a light may be seen under the existing meteorological virility conditions. This does not take the height of the light, the overseas heat or the curvature of the Earth into consideration. It is only based on the intensity of the light.
85
With regards to lighted navigational aids, the nominal range is
the maximum distance a light can bee seen in clear weather, which is defined as a visibility of 10 nautical miles. This only depends on the intensity of the light
86
Are oil well strictures listed on the Light List?
No
87
What is the primary means for disseminating information concerning aids to navigation, hazards to navigation and other items of marine information of interest to mariners not he waters of the U.S.
Local Notice to Mariners (LNM)
88
Who is responsible for developing and issuing the LNMS?
Each Coast Guard District with information received fromCoast Guard field units, the general public, the Army Corps of Engineers, U.S. Merchant Fleet, National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), and other sources, concerning the establishment of, changes to, and deficiencies in aids to navigation and any other information pertaining to the safety of the waterways within each Coast Guard District. This information includes: Reports of channel conditions, obstructions, hazards to navigation, dangers, anchorages, restricted areas, regattas, information on bridges such as proposed construction or modification, the establishment or removal of drill rigs and vessels, and similar items.
89
a series of nautical books that cover a variety of information important to navigators of coastal and intracoastal waters and the Great Lakes. Issued in nine volumes, they contain supplemental information that is difficult to portray on a nautical chart.
The United States Coast Pilot
90
Topics in the Coast Pilot include
Channel descriptions, anchorages, bridge and cable clearances, currents, tide and water levels, prominent features, twofers, pilotage, weather, ice conditions, wharf descriptions, dangers, routes, traffic separation schemes, small-craft facilities and Federal regulations applicable to navigations
91
a reference publication depicting basic chart elements and explains nautical chart symbols and abbreviations associated with NOAA and NGA charts.
Chart No. 1: Nautical Chart Symbols, Abbreviations and Terms. The Tenth Edition dated November 1997 is the current edition number.
92
The direction and velocity that a vessels moved off of its intended course due to the effects of wind and current are
set and drift
93
Anticipated set and drift can be determined by
eferencing a variety of publications, including current charts, PC-based current programs, and the current tables produced by the National Ocean Survey (NOS) branch of NOAA.
94
With a GPS coupled with an autopilot, the effects of set and drift (called “cross-track error” in GPS terminology) can be
compensated for automatically, saving considerable time, and fuel, in a long journey.
95
The Dead Reckoning Plot conoids of only two elements
course and speed
96
If offshore waters DR plots are often calculated for
every hour or half hour. In restricted waters every 15 minutes
97
Dead Reckoning is your intended or assumed path through the water. Dead Reckoning is based on: a, COURSE (direction traveled in either TRUE or MAGNETIC) b, SPEED & TIME (distance run)
98
A dead reckoning is
```
prepared as you go
reflects actual progress
reflects actual starting time
reflects actual fixes
reflects near term planning is updated after each fir
```
99
A new DR plot me be started after
every good fix, or course or speed change.
100
STW =
peed through the water.
| Do NOT consider the effects of Current or the effects of Wind
101
COA
Course of Adance. The direction of the intended path over ground
102
SOA
Speed of Advance. The speed intended to be made over ground along the COA
103
COG
Course Over Ground, Instantaneous direction of the actual path over ground
104
SOG
Speed over ground. Speed made good at any instant along the
105
STW
Speed through water
106
CMG
Course Made Good. The resultant direction fro the beginning of the voyage to the end.
107
SMG
Speed made good. The overall actual speed of the voyage
108
EP
Electronic position. This is your real position (Fix)
109
PTA
Point to Aim. This is the course to steer to adjust for the current (PSC).
110
Purpose of a DR Plot
a, Before sailing (voyage planning):
b, Determine course and speed to make.
c, Identify checkpoints and waypoints,
d, Locate fuel and other needed stops.
e, Estimate: Fuel, time, and other parameters.
f, While underway to plot or follow actual progress.
111
RULES FOR A DR PLOT
1, A DR plot is based only on course and speed through the water
2, A DR position is plotted at convenient time intervals , eg every 30 or 60 minutes
3, A DR position plotted whenever a fix, running fix, or line of position is determine
4, A DR position plotted whenever a course or speed change occurs
5, A new DR plot should be started whenever a fix or running fix is obtained
112
BOW BEAM BEARINGS
When running along the coast within visual sight of land, there is a simple method of determining distance offshore, which may be necessary to avoid a shoal or other navigational hazard. This method is called bow beam bearings, and sometimes called “doubling the angle on the bow.”
This method is based on the geometric fact that two sides of a 45° right triangle are equal. When some landmark (lighthouse, tank, etc) at or near the shoreline bears 45° relative, make note of the time and vessel speed. When the landmark is at 90° relative, the distance from the time of the first sighting is equal to the distance off.
113
RUNNING FIX
Inevitably, there will be times when a sufficient number of landmarks are not available to take a 3-LOP fix, either due to weather, insufficient landmarks, or when landmark angular separation is unsatisfactory. In these instances, a single LOP can be “advanced” to create a reliable fix.
