Military

 

Chapter 5

Charts and Publications

The mariner must be able to identify and describe the following:
  • Basic charts used aboard ship.
  • Chart numbers.
  • Correct charts.
  • Basic navigation publications.
  • Agencies that are responsible for updating, publishing, and issuing charts and publications.
The mariner must also be able to interpret chart numbers, use basic navigation publications, and know how to requisition charts and publications.

THE EARTH AND ITS COORDINATES

  5-1. This paragraph describes the earth and its basic reference lines which are required for locating a geographical position in terms of latitude and longitude. It also tells how to measure distance and direction. You need to know this information to be able to solve problems in navigation.
TERRESTRIAL SPHERE

  5-2. The earth is called the terrestrial sphere (Figure 5-1). Although it is a little flattened at the poles instead of being perfectly spherical, this irregularity is disregarded here for simplicity. Reference points for location of objects on earth, with two exceptions, have been established by general agreement among maritime nations. The two exceptions are the North and South Poles, located at the ends of the axis on which the earth rotates. Imaginary lines (an infinite number of them) running through the poles and around the earth are called meridians (these divide the earth into sections).
  5-3. If you start at the North Pole and travel along a meridian exactly halfway to the South Pole, you will then be on the equator (an imaginary line running around the earth). The equator bisects every meridian and divides the earth in half. The half the North Pole is located is called the Northern Hemisphere and the half the South Pole is located is called the Southern Hemisphere.


Figure 5-1. Terrestrial Sphere

CIRCULAR MEASUREMENT
  5-4. You must know something about how distances are measured along the circumference of a circle. Measurement along a meridian, which is a great circle, is expressed in terms of degrees of arc. These degrees of arc may be transformed into linear measurement expressed in nautical miles. The best example of circular measurements in degrees of arc is the compass card. Whatever the size of the card, its circumference is always 360 . Each degree contains 60 minutes ('), and each minute has 60 seconds ("). The nautical mile, by arbitrary international agreement, is now taken as 6,076.11549 feet or exactly 1,852 meters. The nautical mile is about one-seventh again as long as the statute mile.
MERIDIANS AND PARALLELS
  5-5. In developing a system for locating points on the terrestrial sphere, there are a series of meridians running through the poles of the earth and a single line called the equator, running around the earth at right angles to its axis. These reference lines can be seen in Figure 5-2. The equator divides each meridian and the earth itself into two exact halves.


Figure 5-2. Equator

  5-6. There is a meridian (360 of them) for each degree around the earth's rim. A starting point for numbering these meridians was required, and most of the maritime countries decided that the starting point should be the meridian passing through the Royal Observatory at Greenwich, England. The Greenwich meridian is therefore number 0; meridians run from that meridian east and west to the 180th, on the opposite side of the earth from Greenwich. The complete circle formed by the 0 and the 180th meridians, the prime meridian, like the equator, divides the earth into two exact halves, the Eastern and the Western Hemispheres (Figure 5-3). Meridians run true north and south.
  5-7. If you cut a globe of the world in half exactly along the equator and then lay the top portion on a flat surface, the flat edge appears as a straight line. This top portion (now as a semicircle) contains 180 of arc, 90 from the equator to the pole on either side.
  5-8. Beginning with the equator, you see lines that appear to be parallel to it, one for each of the 90 of arc from the equator to the North Pole. The planes forming these lines on the earth's surface are actually parallel to each other, and for this reason they are called parallels. If you shift your eye to a point just above the pole, you can see that they are actually circles, growing increasingly smaller as they get farther from the equator and nearer the poles. Remember that no matter how small a circle is, it still contains 360 . However, the distance represented by each degree becomes less as the parallel circles get smaller.


Figure 5-3. Prime Meridian

  5-9. Do not think that there are only 360 meridians and 180 parallels. There is a meridian or parallel for every one of the 21,600 minutes around the complete circle of the earth's sphere.
  5-10. The parallels and meridians are imaginary, but there is a limit to the capacity of our instruments. We seldom break down a measurement along a meridian or parallel to a value smaller than that of one second.
GREAT CIRCLE
  5-11. A great circle is any circle whose plane passes through the center of the earth or any other sphere. The plane separates the sphere into two equal imaginary parts.
  5-12. Suppose you have a perfect sphere of soft rubber through which you can pass a flat sheet of thin metal. If you shove the metal sheet through the sphere so as to cut it exactly in half, you have passed it through the center (see Figure 5-4). The circumference of the flat side of each half becomes a great circle whose circumference is the same size as the circumference of the sphere itself.
  5-13. However, if you shove the flat metal through the sphere so that it does not pass through its center, the circumference of the flat side of each part is smaller than the outside circumference of the sphere.
  5.14. In both examples cited, the flat sheet represents the plane of the circle the sheet makes when it cuts the sphere. If you were to cut the earth on a similar plane, no matter how it is spliced, if the plane passes through the earth's center, the cut off circle is a great circle. If the plane passes through the earth away from the center, the circle it cuts is a smaller circle.
  5-15. The equator is a circle whose plane passes through the earth's center. Therefore, the equator is a great circle, and it is the only parallel that is a great circle. The other parallels N and S of the equator are all smaller circles whose planes do not pass through the earth's center. All meridians, on the other hand, pass through the poles, and all their planes must therefore pass through the earth's center. Therefore, every meridian is a great circle.
  5-16. Do not think that a great circle must be either a meridian or a parallel. A great circle is any circle around the earth whose plane passes through the earth's center, no matter in what direction the plane passes. The practical significance of the great circle in navigation is that it is the shortest distance between two points on the earth along the great circle passing through those points.


Figure 5-4. Great Circle Equator

LATITUDE AND LONGITUDE
  5-17. Now we have a network of meridians and parallels all the way around the globe. Every spot on the earth is located at the point of intersection between a meridian and a parallel. Every point's location is described in terms of the following:
 
  • Latitude (in degrees, minutes, and seconds of arc north [N] or south [S] of the equator, measured along the point's meridian).
  • Longitude (in degrees, minutes, and seconds of arc east [E] or west [W] of 0 meridian, measured along the point's parallel).
  Longitude is always from 0 to 180 E or W. Latitude is never greater than 90 N or S. Zero latitude is the equator. If you are at latitude 90 N, you are at the North Pole, and whichever way you look is south.
MEASURING DISTANCE
  5-18. The nautical mile is almost equal to 1' of arc on the equator. This is about 1 1/7 statute or land miles. The equator is a great circle. So, if 1' of arc on the equator is 1 nautical mile, 1' of arc on any great circle must also be 1 nautical mile. All great circles are the same length.
  5-19. This means that on any chart, the meridians may be used as a distance scale. All meridians are great circles; 1' of latitude along any meridian equals 1 nautical mile. However, when it comes to parallels, 1' equals 1 mile only on the equator, the only parallel that is a great circle. To put it another way, 1' of longitude equals 1 mile only on the equator.
SPEED
  5-20. The word "knots" is a seagoing speed term meaning nautical miles per hour. It is incorrect to say "knots per hour" except when referring to acceleration.
DIRECTION
  5-21. Nautical direction is usually measured from true north on the observer's meridian.
  5-22. On the old-fashioned compass card (Figure 5-5), direction was indicated by points. There were 32 major points around the card, each of which had a name: N, N by E, NNE, NE by N, NE, and so on. Each point was subdivided into quarter points, a point equaled 11.25 degrees of arc. The system of naming these divisions toward or away from the points themselves was complicated and difficult to remember. You will still find the system used in our Rules of the Road. Referring to the arc of a light for example, the light may be seen from ahead to "two points abaft the beam."


Figure 5-5. Compass Card

  5-23. Navigators have long since adopted the system of circular measurement (360 of arc) as a more convenient means of indicating direction than the ancient system of points.
  5-24. Direction in modern navigation is always given in degrees and measured clockwise from true north or 000 T. A course or bearing is always expressed in three figures, regardless of whether three digits are necessary (for example, it is not 45 , but 045 ). Seldom is it possible to consider compass direction to a value smaller than the 10th of a degree even though each degree of direction contains 60 minutes of 60 seconds each. It is almost impossible to read a compass bearing or heading closer than a quarter of a degree.
  5-25. A true bearing is the direction of an object from the observer measured clockwise from true north.
  5-26. A relative bearing is the direction of an object from the observer measured clockwise from the ship's head, as indicated by the lubber's line in the binnacle, pelorus, or gyro repeater.
  Note: There will be times when you will find it necessary to convert from true to relative bearings and vice versa. This relationship is shown in Figure 5-6. Notice that dead ahead is 000 , dead astern is 180 , and the starboard and port midpoints (beams) are 090 and 270 , respectively.
  5-27. The reciprocal of any bearing is its opposite; that is, the point of degree on the opposite side of the compass card from the bearing (for example, the reciprocal of 180 is 000 and vice versa). When you obtain a bearing on an object, the bearing from the object to you is the reciprocal of the bearing from you to the object. To find the reciprocal of any bearing expressed in degrees simply add 180 to the bearing. If the bearing is 050 , for instance, its reciprocal is 050 plus 180 or 230 . If your bearing is greater than 180 , subtract 180 .

THE MERCATOR CHART

  5-28. There is a difference between the terms "map" and "chart." A map shows land areas. It also shows the physical features of the land, cities, towns, roads, political boundaries, and other geographic information. A chart, specifically a nautical chart, shows primarily areas of navigable waters. It also shows coastlines and harbors, depths of water, aids to navigation, channels, and obstructions. A chart provides a means of describing position in terms of latitude and longitude.


Figure 5-6. True and Relative Bearings

  5-29. Gerhardus Mercator developed a method of making a world chart based upon the cylindrical projection. This type of chart (Figure 5-7) is projected by first placing a cylinder around a sphere representing the earth, tangent to the equator (see Figure 5-8). Planes are passed through the meridians and projected to the cylinder upon which they appear to be parallel lines. Lines are then drawn from the center of the earth to the cylinder passing through the parallels; this locates the parallels on the cylinder. The cylinder is then cut lengthwise and flattened out. The resulting graticule (the network of lines of latitude and longitude upon which a map is drawn) is shown in Figure 5-9.


Figure 5-7. Mercator Chart of the World


Figure 5-8. Mercator Projection


Figure 5-9. Meridians and Parallels

  5-30. In the Mercator projection, parallels are spaced by mathematical formulas. In fact, meridians and parallels are expanded as the latitude increases toward the poles. A Mercator projection based on tangency with the equator cannot include the poles.
MEASURING DIRECTION ON A MERCATOR CHART
  5-31. The advantage of a Mercator chart (Figure 5-7) is that it is a conformal chart. The appearance of meridians on a Mercator projection as parallel straight lines is one of the most valuable features of this type of projection. It makes it possible to plot a course as a straight line, called a rhumb line (Figure 5-10). A rhumb line cuts every meridian at the same angle. It is also a line with the same bearing throughout. Although it does not represent the shortest distance between the points it connects, this fact is not important unless very large distances are involved.
MEASURING DISTANCE ON A MERCATOR CHART
  5-32. The disadvantage of a Mercator chart is the distortion at high latitudes. On earth, the meridians actually converge at the poles, while on the Mercator chart they remain parallel. For practical purposes, 1 of latitude everywhere on the earth's surface may be considered to be equal to 60 nautical miles in length; 1 of longitude will vary with the latitude. At the equator, 1 of longitude is equal to 60 nautical miles and zero at the poles (60' equal 1 ). Since 1 minute of latitude is equal to 1 nautical mile everywhere, it is the latitude scale that must be used for measuring distance, never the longitude scale.


Figure 5-10. Rhumb Line

  5-33. When measuring distance over a large area, set the dividers to a convenient scale at the mid-latitude between the two points of measurement. Then step off the distance (Figure 5-11).


Figure 5-11. Measuring Distance

Plotting Position on the Chart
  5-34. A position is usually expressed in units of latitude and longitude, generally to the nearest 0'.1. It may also be expressed as bearing and distance from a known position, such as a landmark or aid to navigation.
  5-35. You can plot the latitude and longitude of a position on a Mercator chart by using a triangle or straight edge and a pair of dividers. For example, the position of "Point X" is latitude 57 09' N and longitude 63 44' W. This may be plotted as shown in Figure 5-12 and as described as follows:
    . Use the dividers to measure off the latitude. Put one leg of the dividers on the closest parallel (57 N) and the other on 09'. The spread of the dividers equals the difference of latitude.
    . Transfer the dividers to the meridian nearest to the desired position to be plotted (65 W), and mark the latitude on the meridian.
    . Place a straight edge through this point parallel to the parallel of latitude. (Lay the straight edge in the direction of the plot.)
    . Set one leg of the dividers on 65 on the longitude scale and the other leg on 64 44' W (a spread of 16').
    . Without changing the spread of the dividers; lay off this distance along the straight, from 65 toward the desired position.
    . Draw a dot, then circle and label the dot.


Figure 5-12. Plotting a Position

Reverse Situation
  5-36. Determine the latitude and longitude of a specific position as shown in Figure 5-13 and as described as follows:
    . Place the point of one leg of the dividers on the position, swing the other point in an arc, and adjust the spread of the leg until it is at right angles to and touches a parallel of latitude.
    . Without changing the spread of the dividers, transfer the dividers to the latitude scale. Put one leg on the reference parallel, put the other leg in the direction of the plot, and read the latitude of the fix at the other point.
  5-37. A similar procedure is used in steps C and D, measuring from the position to a meridian of longitude. This will give the longitude of the position.
  Note: Care must be taken in each case to lay off the distance of latitude and longitude in the right direction from the reference parallel or meridian.
  5-38. Several variations of these procedures may suggest themselves. That method which seems most natural and is least likely to result in error should be used.


Figure 5-13. Determining Latitude and Longitude

SCALE OF CHARTS
  5-39. The scale of a chart refers to a measure of distance, not area. A chart covering a large area is called a small-scale chart (Figure 5-14), and a chart covering a small area is called a large-scale chart (Figure 5-15). Scales may vary from 1:40,000, which are for special charts of inland waters and inland waterways, to 1:600,000, which are the sailing charts. The scales can vary from about 1:2,500 to about 1:5,000,000.

Figure 5-14. Small-scale Chart

Figure 5-15. Large-scale Chart

  5-40. Charts published by National Ocean Survey, which is under the National Oceanic and Atmospheric Administration, Department of Commerce, are classified into series according to their scale.
Sailing Charts - Scale 1:600,000 and Smaller
  5-41. These charts are used when approaching the coast from the open ocean or for sailing between distant coastwise ports.
General Charts - Scale 1:150,000 to 1:600,000
  5-42. These charts are used for coastwise navigation outside of outlying reefs, yet where the vessel will be within sight of land or aids to navigation and where piloting techniques are used.
Coast Charts - Scale 1:50,000 to 1:150,000
  5-43. These charts are used for inshore navigation, entering large bays and harbors, and navigating large inland waterways.
Harbor Charts - Scale Larger Than 1:50,000
  5-44. These charts are used in harbors, anchorage areas, and smaller inland waterways.
Small-Craft Charts - Scale 1:40,000 and Larger
  5-45. These small-craft charts are strip charts of inland waters to include the intracoastal waterway.
  5-46. Charts published by the Defense Mapping Agency Hydrographic and Topographic Center are classified into two categories: Approach Charts - charts of 1:150,000 and less and General Charts - roughly 1:150,000 and larger.
  5-47. Good seamanship requires that you use the largest scale chart available for study of your proposed voyage, even though you may use smaller scale charts for doing your plotting.
BASIC INFORMATION SHOWN ON CHART
  5-48. The chart's legend will show the title of the chart which describes the waters covered; type of projection used; the scale; unit of measurement used for water depths (feet, fathoms, or meters); and the datum plane for the soundings (Figure 5-16).
  5-49. Also on the chart (where space is available) other useful information can be listed. This information could include the meanings to special abbreviations, cautions, special markings, and any other information that may be of value to the mariners. Boxes and notes may be printed in the margins or on the face of the chart at locations where it will not block out other navigational information.
EDITIONS AND REVISIONS
  5-50. The edition number and the date of the last revision will always appear in the lower, left-hand corner of the chart along with the chart number (Figure 5-17).
COLOR AND LETTERING
  5-51. Land areas are shown in a buff or yellowish color. On DMAHTC charts, land areas are shown in a gray tint. Shallow or shoal waters are shown in blue, and deep water areas are shown in white. Areas that may be submerged at some tidal stage, such as sandbars, mud flats, and marshes are shown in green. The color "magneta" is used for most information listed on the chart because it is easier to read under red nightlights.
  5-52. By knowing the type of lettering being used, you can more easily and quickly interpret the type of information being presented.
Upright or Roman Lettering
  5-53. Identifies features that are dry at highwater.
Slanting or Italic Lettering
  5-54. Identifies submerged or floating hydrographic features (this does not include sounding figures, showing depth).


Figure 5-16. Chart Legend


Figure 5-17. Edition Number on Chart

DEPTH
  5-55. Depth is shown on a chart by many small printed figures, indicating the depth of water at that point in either feet or fathoms. A few charts may mix these units, using feet in the shallower areas and fathoms offshore in deeper waters.
  5-56. Some of the newer charts being published by DMAHTC, and to a lesser extent by NOAA, will have soundings and land measurements shown in meters. Therefore, always check the legend of the chart to be sure of the units used for measurement.
CHART SYMBOLS AND ABBREVIATIONS
  5-57. There are many symbols and abbreviations used on charts (see Appendix A for nautical chart symbols and abbreviations). These symbols and abbreviations are a type of graphic shorthand to tell you the physical characteristics of the area and the details of the available aids to navigation. Depending on the series or scale of chart used; these symbols and abbreviations are standardized, but are subject to some variation. On large-scale charts, the characteristics of lights are shown (see Table 5-1).

Table 5-1. Characteristics of Lights

CHARACTERISTICS EXAMPLE MEANING
Character Gp F1 group flashing
Color R red
Period (2) 10 sec two flashes every 10 seconds
Height 160 ft 160 feet
Range 19M 19 nautical miles
Number "6" light number 6
     

Note: The chart legend for this light would appear as follows: Gp F1 R(2) 10 sec 160 ft 19 M "6".

UNITED STATES NAUTICAL CHART NUMBERING SYSTEM
  5-58. The United States Nautical Chart Numbering System applies to all nautical charts produced by the DMAHTC and NOAA. The chart numbering system provides a simple method of identifying each chart by number. This number shows, in general, the geographical region and scale range in which the chart falls. Charts numbered with one to five digits are shown in Table 5-2.

Table 5-2. Chart Numbering System (One to Five Digits)

CATEGORY NUMBER OF DIGITS NATURAL SCALE
1 ONE (1-9) No scale involved
2 TWO (10-99) 1:9,000,001 and smaller
3 THREE (100-999) 1:2,000,001 to 1:9,000,000
4 FOUR (5,000-9,999) Nonnavigational type
5 FIVE (11,000-99,999) 1:2,000,000 and larger

  5-59. From the list indicating number of digits and associated scale, four categories of charts exist. Each category contains clues to the location and scale range of the chart.
Charts With One-Digit Numbers
  5-60. These charts have no scale and include charts showing nautical chart symbols and abbreviations, national flags and ensigns, and international flags and pennants with Morse symbols.
Charts With Two- and Three-Digit Numbers
  5-61. These are general charts, based on the nine "ocean basin" concept (see Figure 5-18).


Figure 5-18. World Ocean Basins Area

5-62. The first digit in the category denotes the ocean basin which the chart covers. Two-digit numbers (10-99) are used for charts with a scale of 1:9,000,001 and smaller. The three-digit numbers (100-999) indicate charts with a scale between 1:2,000,001 and 1:9,000,000. An exception to the scale concept is the series of position plotting sheets, which have a scale larger than 1:2,000,000. These plotting sheets have been included in the three-digit number category because they cover ocean basins of 360 of longitude. Since the Mediterranean (basin 3), the Caribbean (basin 4), and the Indian Ocean (basin 7), for example, are small in size, an exception to the ocean basin concept exists. There is no chart smaller in scale than 1:9,000,000 in these areas. The two-digit numbers 30 to 49 and 70 to 79 are used for special world charts that cannot have the first digit indicating an ocean basin, such as the Magnetic Inclination or Dip, chart (30); Magnetic Variation, chart (42); and the Standard Time Zone Chart of the World, chart (76).
Nonnavigational Charts With Four-Digit Numbers
  5-63. These are special-purpose chart series such as chart 5006, Chart of the World, Longitude 172 W to 15 E; and chart 5090, Maneuvering Board.
Charts With Five-Digit Numbers
  5-64. Since the charts in this category have a scale range of 1:2,000,000 and larger, the "ocean basin" concept loses significance, so another system was adopted, based on the world now divided into nine regions as shown in Table 5-3.

Table 5-3. World Regions

REGIONS GENERAL AREA
1 UNITED STATES AND CANADA
2 CENTRAL AND SOUTH AMERICA AND ANTARCTICA
3 WESTERN EUROPE, ICELAND, GREENLAND, AND THE ARCTIC
4 SCANDINAVIA, BALTIC, AND RUSSIA
5 WEST AFRICA AND THE MEDITERRANEAN
6 INDIAN OCEAN
7 AUSTRALIA, INDONESIA, AND NEW ZEALAND
8 OCEANIA
9 EAST AFRICA

  5-65. The five-digit category contains all the large-scale charts of the world. These are the primary nautical charts. The first of the five digits indicates the region in which the chart is depicted, the second digit indicates a geographical subregion within the region, and the last three digits identify the geographical order of the chart within the subregion.
CARE OF CHARTS
  5-66. Charts are one of the most important aids to the navigator, and they must be treated as such. Charts should be kept dry and clean.
  5-67. Permanent chart corrections should be made in ink so that they cannot be erased. All other lines and markings should be made in pencil so that they can be erased. To avoid confusion, lines drawn on a chart should be drawn no longer than necessary and they should be labeled. After you have finished using the chart, all lines should be erased. The chart should be inspected for damage and stored flat with the least amount of folding.
  5-68. Charts are stored in a drawer or kept in a portfolio. They should be properly indexed so that any desired chart can be found when needed.

CHART PORTFOLIOS

  5-69. The chart portfolio system divides the world into 52 geographical areas. This system assigns a two-digit designator that represents a portfolio number to each area (see Figure 5-19).
  5-70. An "A" and/or "B" prefix is also used. The "A" series of portfolios contain all the general charts and the principal harbor and approach charts for each of the 52 geographical areas. The "B" series of charts supplement the "A" coverage. To determine the chart portfolio number, locate the DMA stock number in the lower right-hand corner of the chart. Figure 5-20, shows the system used to establish the portfolio and sequence of chart numbers within the portfolio. The last three digits of the chart number show the chart number within the subarea.


Figure 5-19. World Subregions


Figure 5-20. Lower Right-Hand Corner of Chart

CORRECTING A CHART

  5-71. The date printed on the lower left-hand corner of the chart (Figure 5-21) is the date of the latest Notice to Mariners used to update the chart. After this date, the responsibility for updating the chart belongs to the user. The weekly Notice to Mariners will list corrections to be posted on charts as they occur.


Figure 5-21. Lower Left-hand Corner of Chart

  5-72. The weekly Notice to Mariners presents corrective information affecting charts as well as Coast Pilots, Sailing Directions, fleet guides, catalogs of nautical charts, light lists (USCG and DMAHTC), radio navigational aids, and other publications as may from time to time require updating.
  5-73. Chart corrections are listed numerically by chart number, beginning with the lowest and progressing through all charts affected. Each correction pertains to a particular chart and that chart only. Related charts, if any, have their own corrections which, in turn, pertain to a single chart only.
  5-74. The following paragraphs and the example in Figure 5-22 explains the individual elements of a typical correction.
  5-75. A correction preceded by an asterisk (*) indicates it is based on original US source information, the letter "T" indicates it is temporary, and the letter "P" indicates it is preliminary.
  5-76. Courses and bearings are given in degrees clockwise from 000o true. Bearings of light sectors are toward the light.
  5-77. The visibility of lights is usually the distance that a light can be seen in clear weather and is expressed in nautical miles. Visibilities listed are values received from foreign sources. The visibility of lights maintained by the USCG is given as "nominal range."


Figure 5-22. Explanation of Format

CHART/PUBLICATION CORRECTION RECORD CARD
  5-78. Before changing any chart, you should go through the Chart/Pub Correction Record (DMAHC-8660/9) cards (Figure 5-23) and remove those affected by that particular notice. After withdrawing the cards corresponding to the number entered on the chart correction list, you are ready to enter the necessary data on the cards. Prepare a card for each chart/publication by inserting the following information:
 
  • Chart/publication number.
  • Portfolio.
  • Edition number/date.
  • Classification.
  • Title of chart/publication (if title is too long, use an abbreviated descriptive title).


Figure 5-23. Chart/Pub Correction Record (DMAHC-86609)

STEPS FOR UPDATING RECORD CARD
 

5-79. Perform the following when updating the record card.

 
  • Review section I of the current Notice to Mariners and determine which charts on board are to be corrected.
  • Get the chart/publication correction record card for each chart to be corrected.
  • Make corrections in ink on chart.
  • Post chart/publication correction record card, date, and initial.
  • Make notation on lower left-hand side of chart, showing date of correction and Notice to Mariners number.
  5-80. Each chart on board will have a chart correction card on file. With the chart correction card system, only the charts in current use in the operating area of your ship must be kept up-to-date at all times. Corrections are not made to other charts until the charts are needed. If a chart is not corrected, a notation is made on the card. The entry gives the Notice to Mariners number and page number. When a chart is corrected, the date and the initials of the person who corrected the chart are entered in the prescribed spaces on the card.
  5-81. The weekly Notice to Mariners features a new format for presenting corrective information affecting charts, Sailing Directions, and US Coast Pilots. In section I, chart corrections are listed by chart number, beginning with the lowest and progressing in sequence through each chart affected. The chart corrections are followed by publication corrections, which are also listed in numerical sequence. Since each correction pertains to a single chart or publication, the action specified applies to that particular chart or publication only. Related charts and publications, if any, are listed separately.
  Note: In correcting charts that have accumulated many corrections, it is more practical to make the latest correction first and work backwards. The reason for this is because late corrections may cancel or alter earlier corrections.
  5-82. Upon receipt of a new chart and/or a new edition, a new card should be made so that the card will show only those corrections (including temporary changes) which have been published since the date to which the chart was corrected by the DMAHTC. Temporary changes are not incorporated in new editions of charts and must be carried forward from old editions. Consult Notice to Mariners 13, 26, 39, and 52 for outstanding temporary corrections. At the end of each quarter, the DMAHTC will include in the Notice to Mariners a chart correction list for that quarter containing all effective Notice to Mariners corrections to charts. The list for Navy Notice to Mariners corrections will be published annually. These lists should be checked against the cards to make sure that all corrections have been entered.
CHART CORRECTION TECHNIQUES
  5-83. The first step in correcting a chart is usually to erase that part of the charted information that will be changed. Lay the chart on a smooth area. Erase in a back and forth motion with an abrasive eraser (this should remove most of the ink). To preserve the quality of the paper's surface, remove the remainder of the ink with a nonabrasive eraser. Most typewriter erasers are very abrasive and general erasers are mildly abrasive. A sharp penknife or razor blade can be a valuable tool in the hands of an experienced draftsman, but poor handling of a knife can quickly ruin a chart. Rubbing an erased surface with an ivory or bone burnishing tool, or even the thumbnail, may improve its inking qualities. The ink from a conventional lettering or drafting pen tends to feather to a degree, depending on the condition of the erased surface. Normally, a ballpoint pen with a fine point, feathers less and reduces the possibility of ink smears. Another advantage of the ballpoint pen is the variety of colored inks available. Although black is the principal color used in chart correction work, other colors such as green, purple, magenta, or blue may be occasionally needed.
  5-84. Corrections in writing should be kept clear of water areas as much as possible, unless the objects referred to are on the water. When inserting written corrections, care must be taken not to obliterate any of the information already on the chart. When "notes" are to be inserted (such as cautionary, tidal, and so forth), they should be written in a convenient but conspicuous place, where they will not interfere with any other details.
  5-85. The year and number of every Notice to Mariners from which corrections have been made are to be entered in ink at the lower left-hand corner of the charts (for example, "1968-6, 9, 18"). Temporary changes should be made in pencil.

REQUISITIONING PROCEDURES FOR CHARTS

  5-86. DMAHTC is responsible for providing navigational charts and publications to the DOD and civilian users. The DMA requisitioning requirements are designed primarily for DOD activities as a means of simplifying the control of inventories and to reduce order processing time.
GENERAL
  5-87. The requisitioning procedures outlined below are an integral part of the DADMS and cover requisitions by both DOD and non-DOD activities. DOD activities authorized to request DMA products must obtain a DOD activity address designator code through their respective service or agency.
REQUISITION FORMS
  5-88. Use any one of the following forms, which are shown in Appendix B, when ordering DMA products:
 
  DOD activities should use any one of the above forms that best fit their individual needs.
  Note: Use SF 344 to requisition items not identified in DMA publications (1-N-A and 1-N-L) or items where the stock number is not known. When used in this manner, the item description may be written across the entire line or lines under requisition data without regard to columnar headings. Such data as the quantity, serial number, supplementary address, and signal and advice codes will be entered directly below the item description in the appropriate blocks.
PREPARATION OF REQUISITIONS
  5-89. Requisition documents (DD Form 173/1, DD Form 1348, DD Form 1348M, and SF 344) will be prepared as shown in Appendix B.
REQUISITIONING OF NAUTICAL CHART PORTFOLIOS
  5-90. To preclude the submission of many requisition documents when an entire nautical chart portfolio is desired, the requestor may prepare a single requisition identifying the portfolio in the first five positions of the stock number followed by the word "ALL" in the next three positions. The DADMS will generate a requisition for each nautical chart included in the portfolio applying the basic requisition information to each item including document number and quantity requested. Validation, status, manifesting, and issue will be accomplished on a line item basis. Requisitions of this type can be submitted only to the DDCP, DMA Office, Pacific, and DMA ODS branch offices. Examples of portfolios include the following:
 
  • Standard Nautical Chart Portfolios:
    • Portfolio 11A--order as 11AXXALL.
    • Portfolio 37B--order as 37BXXALL.
    • Portfolio 97A--order as 97AXXALL.
  Note: This same sequencing will be used in requisitioning any of the designated nautical chart portfolios included in this catalog.
 
  • World Portfolios:
    • Portfolio WOA--General Charts of the Atlantic--order as WOAXXALL.
    • Portfolio WOP--General Charts of the Pacific--order as WOPXXALL.
    • Portfolio WOB--General Charts of the World--order as WOBXXALL.
SUBMISSION OF REQUISITIONS DOD ACTIVITIES
  5-91. All DOD activities will submit requisitions for DMA products by AUTODIN, message, or mail to the designated source of supply.
Method of Transmitting Requisitions
  5-92. DOD activities having punch card facilities will submit the DD Form 1348M to the designated supply source. Those DOD activities having transceiver facilities may transceive the DD Form 1348M via the AUTODIN. The DD Form 1348M may be mailed if AUTODIN is not readily available.
  5-93. Those activities that do not have punch card equipment or transceiver facilities may use DD Form 1348 or SF 344. These forms will be mailed to the designated supply source. Requisitions forwarded by mail will be identified by the word "MILSTRIP" printed in the lower left corner of the envelope.
  5-94. Message requisitions are acceptable from authorized requisitioners, provided that they are in the format shown. The term "MILSTRIP REQUISITION" will precede the text of the message.
  5-95. Telephone requests from DOD activities are acceptable when the urgency of the requirement dictates. When the telephone is used, the requester will contact the DDCP, overseas depot, DMA field office, or other issuing activity, as appropriate, and provide pertinent data. The issuing activity will record the data on a machinable requisition document and complete processing of the telephone request. Telephone requests from non-DOD activities must be confirmed by letter or message, as such deliveries normally involve reimbursements.
Designated Supply Source
  5-96. The mail and message address, routing identifier, and telephone number of the designated source of supply for nautical products is as follows:
  DMA Office of Distribution Services
ATTN: DDCP
Washington, DC 20315
 

Message Address:

  DMAODS WASHINGTON, DCC//DDCP//
Routing Identifier: HM8
DODAAD: HM0028
Telephone: DSN 287-2495 or 287-2496
COML: (202) 227-2495/227-2496

PUBLICATIONS

  5-97. Every ship must carry the charts and publications required for its safe operation. These include the COMDTINST M16672.2C (Navigation Rules -- International-Inland), all charts applicable for the vessel's navigational area of operation, and all TMs, FMs, and ARs that apply to the class of vessel. The following discusses the various publications and the agencies responsible for publishing them.
THE NATIONAL OCEAN SURVEY
  5-98. This agency is charged with the survey of the coast, harbors, and tidal estuaries of the US and its insular possessions and is a part of the National Oceanic and Atmospheric Administration, Department of Commerce. It is responsible for issuing the following publications.
United States Coast Pilot
  5-99. The United States Coast Pilot publication consists of nine volumes. These volumes include the following:
 
  • ATLANTIC COAST
    • Eastport to Cape Cod.
    • Cape Cod to Sandy Hook.
    • Sandy Hook to Cape Henry.
    • Cape Henry to Key West.
    • Gulf of Mexico, Puerto Rico, and Virgin Islands.
  • GREAT LAKES
  • PACIFIC COAST
    • California, Oregon, Washington, and Hawaii.
    • Alaska-Dixon Entrance to Cape Spencer.
    • Alaska-Cape Spencer to Beaufort Sea.
Coast Pilot
  5-100. Coast Pilot, besides its standard information on US ports and waterways, contains the following:
 
  • Descriptions of ports and harbors.
  • Pilot information.
  • Quarantine and marine hospital information.
  • Coast Guard stations.
  • Radio services, distances, and bearings.
  • Time signals.
  • Atmospheric pressure, temperature, and wind tables.
  • Rules of the road.
  • Instructions in case of shipwreck.
  • General harbor regulations.
Tide Tables
  5-101. These are published each year for various parts of the world and are published in four volumes. Each volume consists of the following:
 
  • TABLE 1. A list of reference stations for which the tide has been predicted. The time and heights of high and low tides are tabulated for each day of the year for each of these reference stations.
  • TABLE 2. A list of subordinate stations for which the tidal differences have been predicted with respect to a reference station having nearly the same tidal cycle.
  • TABLE 3. A convenient means of interpolation which allows for the characteristics of the tidal cycle. While TABLES 1 and 2 provide times and heights of high and low tides, the state of the tide may be desired for a given time in between.
  • TABLE 4. A sunrise-sunset table at 5-day intervals for various latitudes.
  • TABLE 5. A table that provides an adjustment to change the local mean time from table 4 to zone or standard time.
  • TABLE 6 (two volumes only). A table that gives the zone time of moonrise and moonset for each day of the year at selected places.
Tidal Current Tables
  5-102. These tables are prepared annually in two volumes for various areas to provide predictions of the state of the current. Each volume consists of the following tables:
 
  • TABLE 1. A list of reference stations in geographical sequence for which the current has been predicted.
  • TABLE 2. A list of subordinate stations for which the difference between local current and current at a reference station has been predicted. Above the groups of subordinate stations, the appropriate reference station is listed.
  • TABLE 3. A table that provides a means of interpolation for the state of the current at any time between tabulated times.
  • TABLE 4. A table that gives the number of minutes that the current does not exceed the stated amounts for various maximum speeds.
  • TABLE 5 (Atlantic Coast of North America only). A table that gives information on rotary tidal currents.
Tidal Current Charts
  5-103. The tidal current tables are supplemented by 11 sets of tidal current charts. These charts present a comprehensive view of the hourly speed and direction of the current in 11 bodies of water. These bodies of water include the following:
 
  • Boston Harbor.
  • Narragansett Bay to Nantucket Sound.
  • Narragansett Bay.
  • Long Island Sound and Block Island Sound.
  • New York Harbor.
  • Delaware Bay and River.
  • Upper Chesapeake Bay.
  • Charleston Harbor.
  • San Francisco Bay.
  • Puget Sound (northern part).
  • Puget Sound (southern part).
  They also provide a means for determining the speed and direction of the current at various localities throughout these bodies of water.
Chart Catalogs
  5-104. NOS publishes four catalogs. Each catalog covers the following areas:
 
  • Catalog No. 1. The waters of the Atlantic and gulf coasts, including Puerto Rico and the Virgin Islands.
  • Catalog No. 2. The Pacific coast, including Hawaii, and Pacific islands such as Guam and Samoa.
  • Catalog No. 3. The Alaskan waters, including the Aleutian islands.
  • Catalog No. 4. The Great Lakes and the adjacent waterways.
  Each catalog contains several small-scale outline charts with lines showing the limits of each nautical chart in that region.
DEFENSE MAPPING AGENCY HYDROGRAPHIC AND TOPOGRAPHIC CENTER PUBLICATIONS
  5-105. The identification of charts, publications, and other products of DMAHTC is based on a numbering system of one to five digits without a prefix. The number will be based on the scale and on the basis of region and subregion.
  5-106. Publications will continue to carry the "HO" prefix until they are reprinted by DMAHTC. At that time, DMAHTC will assign a number and give the prefix "pub."
Portfolio Chart List
  5-107. The portfolio chart list (