Lesson 3A: Basic Plotting

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Lesson 3A Basic Plotting
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Lesson 3A Basic Plotting

• AGENDA
• Basic chart features
• Traffic separation scheme
• Visual aids
• Tabulated depth charts
• Scales
• Plotting on a chart

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CHART NOTES, CHARACTERISTICS AND SYMBOLS

• Traffic separation Schemes
• Indicate outbound and inbound waterways.
• Magenta in color

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Traffic Separation Scheme
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CHART NOTES, CHARACTERISTICS AND SYMBOLS

• Navigation Aids
• Aids with sound and visual characteristics.
  Listed and labeled on chart
• Usually used as primary navigation
• aids for Visual or Radar.

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Visual Aids Characteristics Label
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CHART NOTES, CHARACTERISTICS AND SYMBOLS

• Notes located throughout the chart give detailed
  descriptions of danger, obstructions, depths,
  overhead clearances, etc.

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CHART NOTES, CHARACTERISTICS AND SYMBOLS

• Scale Conversion Tables
• Used for measuring distance (based on the scale
  of chart being used).
• Used for converting U.S. system of measurement to
  metric, etc.

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Tabulated Depths
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Measuring Distance
NEVER use the longitude scale to determine
distances on a chart.
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TERMS AND DEFINITIONS

• Navigation Plot A graphic plot of the
  movement of a vessel suitably labeled with
  respect to time, direction, and speed.

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TERMS AND DEFINITIONS

• Course The direction in which a vessel is
  steered or intended to be steered.
• Designated as True or Magnetic.

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TERMS AND DEFINITIONS

• Track The path of intended travel
• with respect to the earth as drawn on the
• chart.

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TERMS AND DEFINITIONS

• Speed of Advance (SOA) The speed intended to
  be made good along the track.
• The average speed in knots which must be
  maintained during a passage to arrive at a
  destination at an appointed time.

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TERMS AND DEFINITIONS
PIM-

• Planned track movement based on required SOA
• USS Indianapolis
• Indicated every 4 hours
• Needed for ALL Voyage Plans
• PIM symbol must be different from standard
  navigation symbols. Ex

1200Z PIM
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TERMS AND DEFINITIONS

• Nautical Mile A unit distance used principally
  in navigation. 2000 yards equals one Nautical
  Mile.
• Knot A unit of speed equal to 1 Nautical Mile
  per hour.

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MEASURING DISTANCE
Distance of 1 NM
1 Degree 60 NM (Nautical Miles) 1 Minute 1
Nautical Mile
DISTANCE ALWAYS MEASURED ON LATITUDE SCALE!
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10 NM
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TERMS AND DEFINITIONS

• View Overall Track (Big Picture)
• Use a small scale chart that encompasses the
  overall area
• Great Circle Sailing
• General (International)

If transiting open ocean
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LABELING

• 1. Visual fix is plotted as a circle.
• 2. Electronic fix is plotted as a triangle.
• 3. DR is plotted as a half circle.
• 4. EP is plotted as a square.
• 5. Composite is plotted as a circle with a
  triangle inside the circle.

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LABELING

• 6.  Course is labels on top or above the
  track line. Referenced in 3 digits and always
  labeled T for TRUE and M for MAGNETIC.
• 7.  Speed is labeled below the trackline and
  always expressed in KNOTS.
• 8.  DR Time is labeled at an angle to the
  track line.
• 9.  Fix Time is labeled in a straight line to
  the fix.

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COURSE EXAMPLE

•  
• C-090ºT (080ºM)
•  
• S-10 KTS
• D-1510 YDS

0900
30
1000
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TRACK EXAMPLE

• C-090ºT(080ºM)
  
• S-10 KTS
• D-1510 YDS

090705Z
090700Z
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Plotting Positions on a Nautical Chart

• Step 1 - Examine the latitude scale on side of
  the chart closest to the desired position.
• Step 2 - Place the metal point of the compass on
  the reference parallel.
• Step 3 - Spread the compass to reach the desired
  latitude and make a mark.

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MEASURING LAT. LONG.

• Charted Latitude and Longitudes are based on the
  SCALE of the CHART itself.

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Plotting Positions on a Nautical Chart

• Step 4 - Examine the longitude scale on side of
  the chart closest to the desired position.
• Step 5 - Place the metal point of the compass on
  the reference meridian.
• Step 6 - Spread the compass to reach the desired
  longitude and make a mark.

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Plotting Positions on a Nautical Chart

• Step 7 - Locate the reference parallel and
  meridian intersection and lightly mark the
  reference parallel with the longitude marked
  position.
• Step 8 - Without changing the spread of the
  compass, place the metal point of the compass on
  the reference meridian.

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Plotting Positions on a Nautical Chart

• Step 9 - Remeasure latitude on the latitude scale
  and place the metal end on point and swing a arc
  so that in crosses the one made for longitude.
• Step 10 - Mark the desired position where the two
  arcs crossed( intersected) and label the position.

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Plotting Positions on a Nautical Chart
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Plotting Positions on different scales of charts.
Coastal Chart
Degrees, Minutes and tenths of a Minute
40 03.9 N
24 51.8 E
1.5-12
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RELATIONSHIP OF TIME/SPEED/DISTANCE
D S x T
T D / S
x
S D / T
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RELATIONSHIP OF TIME/SPEED/DISTANCE

• D S x T
• Distance Equals Speed Multiplied By Time.
• yds 12.0 kt x 3min

1200
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RELATIONSHIP OF TIME/SPEED/DISTANCE

• S D / T
• SPEED REQUIRED EQUALS DISTANCE DIVIDED BY TIME
• kts 12.0 nm / 36m

20.0
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RELATIONSHIP OF TIME/SPEED/DISTANCE

• T D / S
• TIME REQUIRED TO TRAVEL 400NM EQUALS DISTANCE
  DIVIDED BY SPEED.
• 1500yds / 15.0kts

3 min
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PLOT THE FOLLOWING POSITION

• Using chart 12245 plot the following position
• 76º 21 36 N
• 36º 57 50.5 W
• Label as Anchorage 1
• DO NOT ERASE THIS MARK!!

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QUESTIONS?