LAB 1: Navigational Pubs and Chart Reading

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LAB 1 Navigational Pubs and Chart Reading

• Learning Objectives
• Know how charts are catalogued in the Defense
  Mapping Agency Catalog of Maps, Charts, and
  Related Products and the NOS Nautical Chart
  Catalog.
• Know the contents of the reference publications
  COAST PILOTS SAILING DIRECTIONS, FLEET GUIDES,
  LIGHT LISTS, LIST OF LIGHTS, TIDE and TIDAL
  CURRENT TABLES, and other important publications.
  
• Comprehend how publications are kept up to date.
• Know hazard and depth symbology used on charts.
• Apply basic plotting techniques on nautical
  charts.
• Applicable reading Hobbs, pp. 51-74.

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Navigational Pubs and Chart Reading

• Navigational Publications
• DMA CATALOG of MAPS, CHARTS, AND RELATED PRODUCTS
• This publication is an illustrated catalog of
  maps, charts, publications and other related
  products produced by the DMA. It contains
  serialized drawings of the world that allow the
  navigator to locate the numbers of all charts and
  applicable Sailing Directions that cover areas of
  interest.
• Most of the Catalog consists of eleven large
  booklets called Volumes. The first nine Volumes
  catalog various charts by geographic region. The
  tenth volume contains information on
  miscellaneous and special purpose navigational
  charts. The eleventh volume is classified SECRET
  and contains classified navigational charts and
  related products,
• Example of the use of the DMA CATALOG A
  navigator is planning to enter Rio de Janeiro,
  Brazil.
• STEP ONE Inspection of a diagram of the worlds
  nine coastal regions indicates that the eastern
  coast of South America lies in Region 2.

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Navigational Pubs and Chart Reading

• STEP TWO Open Volume 2 of the catalog, go to
  page 1 and note the following
• Rio de Janeiro lies in a subdivision marked with
  page 29, and a green subdivision which indicates
  Sailing Directions volume number 23.

Insert Figure 5-1A from Hobbs (page 53)
(Overhead 3-1)
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Navigational Pubs and Chart Reading

• STEP THREE Turn to page seven which provides
  the intermediate scale charts covering approaches
  to Rio (Nos. 24004 and 24008).

Insert Figure 5-1B from Hobbs (page 54)
(Overhead 3-2)
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Navigational Pubs and Chart Reading

• STEP FOUR Turn to page 29 and record the
  large-scale charts covering the approaches and
  harbor of Rio (charts 24160, 24161 and 24162).

Insert Figure 5-1C from Hobbs (page 55)
(Overhead 3-2)
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Navigational Pubs and Chart Reading

• NOS NAUTICAL CHART CATALOG
• These catalogs consist of five separate folded
  sheets printed with graphic drawings similar to
  those in the DMA Catalog. The first four sheets
  cover specific geographic regions of U.S.
  waters. The last one consists of bathymetric and
  special purpose charts.
• COAST PILOTS
• These publications are a series of nine volumes
  (separated by geographic region) that provide
  supplemental information applicable to navigation
  in coastal and intracoastal waters of the U.S.
  and its possessions (the Great Lakes are
  included).
• These publications are extremely valuable when
  planning a voyage as they provide information on
  topographical features, navigation aids, normal
  local weather conditions, recommended tracks,
  pilot information, descriptions of ports and
  harbors, and other useful facts.

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Navigational Pubs and Chart Reading

• SAILING DIRECTIONS
• These publications consist of twelve geographic
  groups of loose-leaf volumes that provide
  information about foreign coasts and coastal
  waters similar to that found in COAST PILOTS.
• The sailing directions are further subdivided
  into 43 publications. Eight of these
  publications are Planning Guides for ocean
  basin transits and the other 35 are Enroute
  directions for piloting in coastal waters.
• DISTANCES BETWEEN PORTS, PUBLICATION NO.151
• This reference lists great-circle distances along
  the most frequently traveled sea routes between
  U.S. and foreign ports and between two foreign
  ports.
• LIGHT LIST
• This publication is a series of seven volumes
  describing lighted aids to navigation, unlighted
  buoys, daybeacons, fog signals, radiobeacons, and
  Loran-C coverage in the coastal and intracoastal
  waters of the continental U.S. and the islands of
  Hawaii.
• LIST of LIGHTS fig 5-9
• This publication is a series of seven volumes
  describing lighted aids to navigation,
  daybeacons, fog signals, and radiobeacons in
  foreign waters and selected coastal waters of the
  U.S.

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Navigational Pubs and Chart Reading

• TIDE AND TIDAL CURRENT TABLES
• Tide Tables are divided geographically into four
  volumes which contain daily tide and time
  predictions for 190 reference stations and time
  and height differences for 5,000 subordinate
  stations (the time and height differences are
  applied to the tide and time values of the
  corresponding reference station).
• Tidal Current Tables are produced in two volumes
  and provide time and current predictions in a
  reference / subordinate station format similar to
  the Tide Tables.
• PILOT CHARTS
• The name of these charts is misleading as they
  cover portions of major ocean basins and not
  piloting waters. These charts are very valuable
  because they provide hydrographic, navigational,
  and meteorological information for a particular
  ocean area.
• FLEET GUIDES
• These publications consist of of two sets of
  booklets that provide naval ships with command,
  navigational, operational, repair, and logistical
  information on frequently visited ports in both
  the U.S and foreign countries.

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Navigational Pubs and Chart Reading

• ALMANACS
• These publications give positions of celestial
  bodies, times of sunrise/sunset, times of
  moonrise/moonset, and other astronomical
  information that is of interest to the navigator.
  
• REFERENCE TEXTS
• The American Practical Navigator (also called
  Bowditch), and Duttons Navigation and Piloting
  are the two primary references used by navigators
  for all aspects of navigation.
• PUBLICATION CORRECTION SYSTEM
• The Notice to Mariners system is used to
  correct/update navigation publications. Each
  publication has a correction card that is updated
  when a Notice to Mariners is received. The
  publication is updated as soon as its use becomes
  necessary.

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Navigational Pubs and Chart Reading

• Chart Reading
• A position of known latitude and longitude can be
  located on a mercator chart using only a compass.
• To plot a given latitude, determine the parallels
  of latitude that bracket the latitude Place the
  pivot point of the compass on the closest line
  and spread the compass until the lead rests on
  the given latitude.
• The compass pivot point is then moved along the
  parallel line until it approximately reaches the
  given longitude. An arc is then swung with the
  crest representing the correct latitude.

Overhead 3-4)
40
70
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Navigational Pubs and Chart Reading

• The same procedure is followed to plot the
  longitude, except that the compass spread is
  taken off the top or bottom scale of the chart.
• The desired position is located at the
  intersection of the two crests.

40
70
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Navigational Pubs and Chart Reading

• Because the latitude scale of a Mercator
  projection expands in length with distance from
  the equator, the length of a mile on the
  latitude scale is not constant.
• Consequently, the part of the latitude scale
  that is at the mean latitude of the distance to
  be measured should always be used to measure
  distance.

B
Mid Latitude
A
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Navigational Pubs and Chart Reading

• All rhumb lines on a Mercator projection
  represent true directions. Measurement of
  direction on a Mercator chart is accomplished by
  using a parallel rule to transfer the direction
  of a rhumb line to a nearby compass rose.
• The reverse process can be used to determine the
  latitude and longitude of a position on the chart
  .
• Place the pivot point of the compass on the
  printed latitude line nearest to the given
  position, and spread the dividers until the other
  point rests on the position. Without changing the
  spread of the compass, shift the compass to the
  most convenient side of the chart, with the pivot
  point still on the chosen printed parallel of
  latitude.
• The longitude is picked off in similar fashion
  using the nearest meridian and the top or bottom
  scale of the chart.

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Practical Work

• Perform Symbol Execise as Group
• Preform Charts/Charts Usage on own
• Perform Lights Work on own