BCH Nav & Piloting Flashcards
In the U.S., the Coast Guard is responsible for servicing and maintaining AtoN under federal jurisdiction.
What Federal regulations code allows the US to conduct aton?
- This includes both short and long-range navigation systems found in the navigable waters, along the U.S. coast, Intracoastal Waterway (ICW) system, and the Western Rivers system.
- 14 USC 81 = In order to aid navigation and to prevent disasters, collisions, and wrecks of vessels and aircraft, the Coast Guard may establish, maintain, and operate:
Lakes and inland waterways that fall under state jurisdiction use?
the Uniform State Waterway Marking System (USWMS).
what does IAM(Aton)LA stand for?
International association of marine aids to navigations and lighthouse authorities. (region B)
USA uses the IALA-? system…
B- NA, SA, japan, south korea and phillipines
IALA-A used by?
Europe, africa, australia, new zealand and most of asia.
What are topmarks?
Small distinctive shapes above the basic aid that assist in the identification of the aid.
When entering from sea which side is A and B system used?
Bravo is red right returning
Alpha is keep red buoys to port
What is the Cardinal system?
The Cardinal System uses a buoy to indicate the location of a danger relative to the buoy itself.
In the U.S., the USWMS uses cardinal marks on waters
where a state exercises sole jurisdiction.
Cardinal marks are not used on waters where the?
U.S. Coast Guard maintains short-range AtoN.
What are the two types of Aton placed in a spot or waterway?
Floating buoy
Fixed beacon
Solid red AtoN buoys and beacons bear and all solid green AtoN ?
red=even numbers, Conical buoys, often referred to as “nun buoys,” are unlighted AtoN. Indicate the left side of the channel.
green=bear odd numbers,Cylindrical buoys, often referred to as “can buoys,” are unlighted AtoN and indicate the right side of the channed
How many specialty buoys are there and how many?
- Fast water buoys
- Disc buoys
- Wx buoys
- Mooring buoys
What is a beacon?
have day-boards attached to a structure that are embedded to the sea bed. Triangle on port square on port.
Red and green lights only have ?
lateral significance
Aton has three colors?
red, green, and yellow/white
How many light characteristics are there?
12
During Restricted Visibility, sound signals are activated by?
- Continuously (bell, gong, or whistle buoy).
- Manually.
- Remotely.
- Automatically (when equipped with a fog detector).
Horns, sirens, whistles, bells, and gongs produce distinct sound signals.
What is retro-reflective material?
Most minor AtoN (buoys and beacons) are fitted with retroreflective material to increase their visibility at night, which is illuminated by light source.
What is Marking channel Junction or Bifurcation?
Red and green, or green and red, horizontally banded buoys and beacons are called preferred-channel marks. used to indicate a channel junction or bifurcation (point where a channel divides or where two tributaries meet).
what is a safe water mark?
Safe water marks are buoys with alternating red and white vertical stripes, and beacons with red and white vertically striped dayboardsmark a mid-channel, fairway, channel approach points and the “In” and “Out” channels of a “Traffic Separation Scheme.” 8 vertical stripes.
What is a isolated mark?
Black and red horizontally banded buoys are called “Isolated Danger Marks” consisting of two black spheres.
what is special marks?
They mark anchorages, dredging/spoil areas, fishnet areas, and other special areas or features.
When a buoy is “watching properly”?
marking its charted position “on Station” and properly displaying all other distinguishing characteristics.
what are beacons? and how many are there?
Beacons are fixed AtoN structures attached directly to the earth’s surface.
- Daybeacons.
- Lighted beacons (minor lights).
- Major lights.
- Light towers.
What is a daybeacon? and how many?
Daybeacons are unlighted fixed structures fitted with a dayboard for daytime identification.
- Single pile with a dayboard on the top.
- Multi-pile structure.
- Tower.
- Structure of masonry or steel.
What is considered a Major light?
Major lights display a light of moderate to high candlepower.
what is a sector light?
Sector lights are sectors of color that are displayed on lantern covers of certain lighthouses to indicate danger bearings. Sector bearings are true bearings and are expressed as “bearings from the vessel towards the light.”
A red sector indicates a vessel would be in danger of running aground on rocks or shoal.
what are ranges?
Ranges are pairs of beacons located to define a line down the center of a channel or harbor entrance.
What is the ICW?
Intra-coastal Waterway Extending some 2,400 miles along the Atlantic and Gulf coasts of the U.S.,
the Intracoastal Waterway (ICW) is a largely sheltered waterway, suitable for year-round use.
Small yellow square and triangle indicate what?
yellow square- kept on left side when traveling N,S, E or W.
Small yellow triangel and triangle indicate what?
yellow triangle- kept on the right side when traveling N,S, E or W.
Non lateral aids in the ICW are marked with what?
yellow horizontal band.
How is the western rivers marked?
western rivers marking system is used on the Mississippi River and tributaries.
1. buoys are not numbered
2. no lateral significance, numbers relate in statute miles.
3. red/white and green/white diamond shaped used for crossings.
Iso danger not used.
The Uniform State Waterway Marking System (USWMS) is designed for use by many types of operators and small vessels on lakes and inland waterways not shown on nautical charts. what are they?
USWMS is considered upstream or towards the head of navigation.
USWMS
Regulatory
Marks?
USWMS regulatory marks are white with two international orange horizontal bands completely around the buoy circumference.
One band is near the top of the buoy while the second band is just above the waterline, four basic geometric shapes.
USWMS
Mooring Buoys
Mooring buoys in USWMS are white with a horizontal blue band midway between the waterline and the top of the buoy, and display a slow-flashing white light when lighted. US also.
Radar
Beacons
RACON is an acronym for Radar Beacon
Morse Code reply when triggered by a boat’s radar signal. RACON transmitter location and extending radially for one to two nautical miles.
Automated
Identification
System (AIS)
The Automated Identification System (AIS) is an internationally adopted radio communication protocol that enables the autonomous and continuous
exchange of navigation safety related messages amongst vessels, lifeboats, aircraft, shore stations, and aids to navigation.
how do AIS communicate?
identity (9-digit Marine Mobile Service
Identity (MMSI) number), position, and status at least every three minutes or as needed.
The Light List is ? a, annual publication providing information on AtoN maintained or authorized by the U.S. Coast Guard located on coastal and inland waters.
seven-volume
light list index indicates 8 categories what are they?
- Number 2. name and location 3. Position
- characteristic 5. height 6.range
- structure 8. remarks
Corrections to the Light List are made in the “Local Notice to Mariners” published by ?
each Coast Guard district.
Navigation is accomplished using a grid system of vertical and horizontal lines that cover the entire globe.
horizontal lines are called? Vertical lines are?
horizontal lines are called parallels of latitude.
The vertical lines are called meridians of longitude.
Great Circles?
A great circle is a geometric plane passing through the center of the earth, which divides the earth into two equal parts.
The earth’s circumference is approximately 21,600 nautical miles. Determine a degree of arc on the
earth’s surface by dividing the earth’s circumference (in miles) by 360 degrees
What is a degree of arc?
In every degree of arc in a circle, there are 60 minutes. Sixty (60) minutes is equal to 1° of arc.
For every degree of arc, there are ?
60 minutes which is (‘) symbol
For every minute of arc in a circle there are?
Circle = 360 degree
1 degree- 60 min
1 min = 60 sec
what are parallels?
Parallels are circles on the surface of the earth moving from the equator to the North or South Pole.
north and south pole are?
North pole =90 degree
South pole = 90 degree
equator = 0 degrees
1 degree of latitude = ?
60 NM
What is a Meridian?
Line that cuts through the earths axis .
The meridian which passes through Greenwich, England, by international convention is called what?
has been selected as 000° and is called the Prime Meridian.
From the prime meridian both east and west are measured out to what degree?
starting from the prime meridian 90 degrees east and 90 degrees west. totally 180 degrees.
A degree of longitute not latitude measures out to what?
60 nm only at the equator
To project an image of the earths surface there are two basic types of projections?
Mercator and Gnomonic
What is mercator projection?
Mercator charts are the primary charts used aboard boats. A Mercator projection is made by transferring the surface of the globe (representing the earth) onto a cylinder
what is a rhumb line?
A rhumb line is an imaginary line that intersects all meridians at the same angle.
Latitude (Lat) and longitude (Long) positions can be reported in three ways.
- Degrees, minutes, seconds: 40° 26’ 46. N, 79° 58’ 56.
- Degrees, minutes, tenths of minutes: 40° 26.767’ N, 79° 58.933’ W
- Decimal degrees: 40.446° N 79.982° W
Compass
Rose
Directions on the chart are measured by using the compass rose. 3 parts to compass rose Inner ring = magnetic outer ring = true variation
what is variation?
difference between true and magnetic North.
On a chart what color is shallow water and deeper water?
shallow = darker blue
deeper water= light blue or white
Edition Number?
edition number and date of the chart is located in the margin of the lower left hand corner.
What scale are sailing charts produced at and in what color?
1:600,000 and purple
What do the colors on a chart represent?
land areas = buff or yellow color
water = white
submerged areas = green
Purple = night vision
Scale charts for Sailing, general, coastal, harbor?
sailing = 1,600,000 general = 1;50,000 to 600,000 coastal = 1;50,000 - 1;150,000 harbor= 1;50,000 and larger small= 1;40,000
Nautical purple ink (magenta) used?
is used for most information since it is easier to read under red light normally used for navigating at night.
what does the slanted lettering mean?
Slanted lettering on the chart is used to label all information that is affected by tidal change or current
basic symbol for a buoy is ?
Diamond and a circle
what is a lighthouse symbol?
black dot with a magenta “flare” giving much the appearance of a large exclamation mark (!)
In order to determine accuracy and completion of a survey what four factors do you need?
- source and date
- testing
- full or sparse soundings
- blank spaces among soundings.
what are the two Electronic chart types?
Vector- which include ENC, DNC and RNC
How many display orientations are there for the chart plotter?
Course up= preferred for monitoring your progress towards a waypoint.
North up= North (000°) is always oriented at the top of the display screen. This mode is useful for navigation planning and when the boat is stationary.
what is GPS?
Global Position System (GPS) is a radionavigation system of 24 satellites operated by the DoD. Once the receiver has computed the range for at least four
satellites, it processes a three-dimensional position that is accurate to about33 meters.
What is D-GPS?
DGPS employs a local fixed reference receiver to correct errors in standard GPS signals.
Corrections are applied within the user’s receiver, providing mariners with a position that is accurate to within 3 meters, with 99.7% probability.
What is WAAS ?
Wide area augmentation service (WAAS) uses a network of ground stations to monitor accuracy of GPS positions.
Error is reported to two master stations which relay to the network for distribution to all WAAS gps receivers.. Reduces 95% error.
What is Course over Ground/Course made Good mean?
direction of movement from one point to another with regard to wind and current.
what is speed over ground or speed made good?
is the speed of travel of a boat along the track, expressed in knots.
How is a radar used?
radar uses radio waves to identify the location, course, and speed of objects. It sends waves to objects then bounces off and returns the info.
What is gain used for?
Gain on the radar is how well a contact or target appears.
What are the three display modes?
Heads up - Available with no compass input as the heading mark points straight upwards.
North up - provided heading information from an electronic or fluxgate compass a radar’s picture can be rotated to put north at the top of the screen.
Course up - Top of the screen represents the course of the boat.
Radar range is?
.125 - 48 nm
Range rings are ?
.5, 1, 2, 4, 8 and 16 nm
Variable range marker?
measures the distance from the boat to a contact using a circle from the center of the radar which is your boat.
Electronic bearing line?
measures the bearing from the boat to a contact using a line of bearing.
What is (ARPA) Automatic radar plotting aid?
Automatic Radar Plotting Aid (ARPA) is a feature that allows you to track the movement of up to 30 radar contacts. Also displays information on the contact.
What is a depth sounder?
The depth sounder is the most accurate way to determine the depth of water. The depth sounder transmits a high frequency sound wave that reflects off the bottom and returns to the receiver. The “echo” is
converted to an electrical impulse and can be read on
Transducer?
transducer is the part of the depth sounder that transmits the sound wave. usually mounted permanently in the bottom or under the transom on the
centerline.
What is the Offset?
Offset is a function available in most depth sounders. its purpose is to compensate for the display of available depth from the sensor location on the hull to the actual lowest point of the vessel
What is the operating mode for Coast guard boats using AIS? 30 mile range…
Secure TX is the primary mode of ops for most government boats.
AIS is equipped with 3 modes. Class A, Tx disabled and Secure TX
Cardinal direction are?
the directions of north,
east, south, and west, commonly denoted by their initials: N, E, S, W.
intermediate directions are northeast (NE), southeast
SE), southwest (SW), and northwest (NW
resulting in a total of 32 named points
What is the reference point using True, magnetic, compass and relative?
True = Geographical north pole Magnetic = magnetic north pole Compass = Compass North Relative = boats bow
Heading sensor is what?
Heading is the direction in which the vessel is pointing at any given moment.
The sensor detects terrestrial magnetism and produces heading data, which is utilized by electronic navigation system components that need accurate and stable heading input such as an electronic charting system and radar.
Heading accuracy is what usually on boats?
Heading accuracy of these sensors is typically ±1°.
Magnetic Compass?
magnetic compass is installed on most boats and is used to determine heading.
What is compass error?
Compass error is the angular difference between a compass direction and its corresponding true direction.
How are errors on the compass fixed?
Errors in variation and deviation are automatically calculated and corrected by a properly calibrated electronic heading sensor.
what is variation?
is the angular difference, measured in degrees, between true and magnetic north.
what is deviation?
Deviation is the amount of deflection influenced by a vessel and its electronics on the compass.
When the compass bearing is ? than the magnetic bearing deviation = ?
less than = error is east.
when the compass bearing is ? than the magnetic bearing deviation = ?
greater than = error is west.
Correcting is going from Magnetic to True?
C D M V T at E
Un-correcting is going from True to Magnetic?
T V M D C at W
What is an electronic fix?
triangle symbol= three or more radar ranges used by electronic equipment.
what is a visual fix?
Circle symbol = common intersection of three or more LOPs (including LOPs from celestial bodies) obtained from simultaneous observations.
what do you do if you cant get a fix?
- Reduce speed 2. take all the way off 3. increase fix frequency 4. turn away from danger.
Two ways to measure distance?
nautical mile - The unit of 2,000 yards is used internationally as the accepted distance of the nautical mile.
The statute mile is used mainly on land, but it is also used in piloting inland bodies of water such as the Mississippi River and its tributaries.
why don’t you use the longitude scale to measure distance?
The longitude scale is never used for measuring distance because the distance between each degree of longitude decreases as you move away from the equator.
How many degree of latitude are from the equator if you travel 1 degree north?
1 degree = 60 nm so 60 nm
20 degrees north = 20x60= 1200 nm
Fixing a boats position by radar is known?
three point fix as it measure the bearing (direction) and/or range (distance) from three landmarks
How do you cross all three radar fixes to get?
When three lines are involved they should all cross at a single point, but in practice they rarely do, instead forming a triangle. The boat’s position is then considered to be on the point or in the center of the small triangle.
Lg triangle means inaccurate measure was taken.
When selecting objects for a radar Fix with only two LOP’s what range is used?
When three lines are involved they should all cross at a single point, but in practice they rarely do, instead forming a triangle. The boat’s position is then considered to be on the point or in the center of the small triangle
an ideal radar fix has?
An ideal fix has three or more LOPs intersecting at a single point and the LOPs have a separation of at least 60°, but not more than 120°.
how to convert true bearings before plotting? Formula=? I’m
True bearaing= ships heading + relative bearing
ex; rb 090 + sh 280 = 370
370-360= 010 degrees
How many Coast Pilots are there?
9 Volumes Atlantic has 1-5 great lakes has 06 pacific has 07 alaska has 08-09
Light list has how many volumes?
07 volumes
Tide tables has?
04 volumes
How many tidal current tables?
02 volumes
Local Notice to mariners is printed by?
printed by the U.S. Coast Guard Navigation
Center, organized by Coast Guard Districts.
Notice to mariners is published?
published weekly by the National Geospatial- Intelligence Agency (NGA).
How many ways can you make recording corrections on a chart?
first way that must be done is to make a cross on the bottom left hand corner of the chart having the LNM and NTM number and date (year on one side and the initials of the person making the correction on the other side).
Or Cut and paste it.
Waypoint is?
A waypoint is a location. It can be a starting point, destination point, or any point in between.
Waypoints are routinely labeled with a cross formed by the intersection of your compass arcs
what is a trackline?
is your intended course plotted on a paper or electronic chart.
When creating tracklines, consult the Fleet Guide and Sailing Directions for recommendations on the best track to use.
when you need to convert (tenths of hours) to minutes you need to?
multiply by 60
.15 x 60 = 60 min
when you need to convert (tenth of hours) to minutes you need to ?
Divide by 60
15/60= .25
to convert .25 multiply by 60 = 15 min
Conveting nm to yards?
36,000/2,000 yds = 18 nm
converting minutes to tenths?
Divide the minutes by 60.
(04) 15 MIN / 60 = .25 HRS
(05) 30 MIN / 60 = .5 HRS
(06) 45 MIN / 60 = .75 HRS
(07) 60 MIN / 60 = 1.0 HRS
Converting tenths to minutes?
Multiply by 60.
(08) .25 HRS x 60 = 15 MIN
(09) .5 HRS x 60 = 30 MIN
(10) .75 HRS x 60 = 45 MIN
(11) 1.0 HRS x 60 = 60 MIN
what is the three minute rule?
yards traveled in 3 minutes divided by 100 equals speed.
reversed
speed, in 3 min, multiplied by 100 equals yards traveled.
To find Speed using the 3 Minute Rule:
Distance (yards) divided by 100 = Speed
800 yds ÷ 100 = 8.0 kts
1000 yds ÷ 100 = 10 kts
1050 yds ÷ 100 = 10.5 kts
To find Distance using the 3 Minute Rule:
Speed multiplied by 100 = Distance (yards)
8 kts x 100 = 800 yards
10 kts x 100 = 1000 yards
10.5 kts x 100 = 1050 yards
what is six minute rule?
Nautical Miles traveled, in 6 minutes, multiplied by 10, equals Speed
or
Speed, in 6 minutes, divided by 10 equals Nautical Miles traveled.
To find Speed using the 6 Minute Rule
Distance (NM) multiplied by 10 = Speed
.8 NM x 10 = 8.0 kts
1.0 NM x 10 = 10 kts
1.5 NM x 10 = 15 kts
To find Distance using the 6 Minute Rule
Speed divided by 10 = Distance (NM)
8 kts ÷ 10 = .8 NM
10 kts ÷ 10 = 1.0 NM
15 kts ÷ 10 = 1.5 kts
Dead reckoning is?
Dead reckoning is the process of estimating your vessel’s position by applying, from your last known established fix.
according to the nav standards each fix be followed by a DR track
of at least two fix intervals.
what is an estimated position?
estimated position is a DR position modified by additional information which in itself is insufficient to establish a fix. Estimated position (EP): A point marked with a small square
what is set and drift?
set is the direction
drift is the speed
Some things to know about river charts?
River charts do not show landmarks such as
stacks, water towers, or antennas.
River charts only show structures immediately on the banks by symbol and footnote.
what is silt in the western rivers?
Silt is a mass of soil particle carried in water. It can clog boat cooling water intakes and wear out strut bearings and shafts. Silt settles on the bottom as shoaling, either adding to or creating sand bars or mud banks.
what is a lock?
Locks release water as a part of their normal operation
what is a dam used for?
Navigation dams release water, as necessary, to maintain a navigable channel during the navigation season.
what does a pro long toooooot mean for a lock?
Enter Lock
what does a short blast of toot mean for a lock?
Leave lock
What do the following colors mean for lock lights?
Red, amber, green,
red = do not enter
amber= approach under control
green= enter lock
flashing amber and green= caution when entering
How is +10 found on the Greenwich scale? How is -10 found on the Greenwich scale?
Greenwich = 0. When you go east it starts with
A +1, B +2, C +3, D +4, E +5, F +6, G +7, H +8, I +9, K +10, L +11, M +12…
Z -0, N -1, O -2, P -3, Q -4, R -5, S -6, T -7, U -8, V -9, W -10, X -11, Y -12
JULIET IS NOT USED!
