1. Navigation NAU 102 Lesson 4

2. Chart Scales Scale – the ratio of a given distance on the chart to the actual distance which it represents on Earth. e.g. 1:80,000 or 1/80,000 1 inch on chart = 80,000 inches on Earth

3. Chart Scales Scale can be stated by: e.g. 1:80,000 or 1/80,000 e.g. “2 inches to the mile” Ratio or fraction A statement A graphic scale

4. Chart Scales Small Scale = Large Area e.g. 1/100,000 vs. 1/10,000 Large Scale = Small Area The larger the scale, the greater the detail.

5. Chart Production National Geospacial-Intelligence Agency (NGA) Charts are produced by the government Formerly National Imagery and Mapping Agency (NIMA) Charts of foreign waters: Lots of other names, too!

6. Chart Production National Ocean Service (NOS) Part of National Oceanography & Atmospheric Administration (NOAA) Charts of US coastal and inland waters:

7. Chart Numbers 1 digit – no scale Charts are numbered with 1 to 5 digits. 2 digits – 1:9,000,001 and smaller 3 digits – 1:2,000,001 to 1:9,000,000 (e.g. Chart No. 1) 4 digits – Special Purpose (e.g. Plotting Sheets) 5 digits – 1:2,000,000 and larger

8. Chart Numbers 1 st digit = Ocean Basin 2 & 3 Digit Charts Cover entire (or most of) ocean basins

9. Chart Numbers

10. 1 st digit = Coastal Region 5 Digit Charts Most common charts, day-to-day use. (Not the same as Ocean Basin) 1 st & 2 nd digits = Subregion Digits 3-5 = Specific Location (Counterclockwise within subregion)

11. Regions and Subregions

12. Chart Numbers

13. Chart Catalogs Free Produced by NGA and NOS Lists authorized sales agents Several volumes, by location Lists all available charts

14. Use of the NGA Catalog Step One: Review the index of the world’s coastal regions/subregions. Example: You are planning to enter Rio de Janeiro, Brazil.

15. Use of the NGA Catalog Rio de Janeiro lies in Region 2

16. Step #2 Locate the Small-scale Coastal Chart Use of the NGA Catalog

17. Step #3 Locate the Harbor Charts

18. Chart Scales Charts are classified by Scale Used for mid-ocean navigation Sailing charts < 1:600,000 General charts 1:150,000 to 1:600,000 Coastwise navigation Outside reefs and shoals

19. Chart Scales Inshore coastal navigation Coastal charts 1:50,000 to 1:150,000 Harbor charts >1:50,000 Small harbors & anchorages Entering Large bays

20. Chart Stock Numbers For purchasing and inventory purposes. 26 = subregion E.g. 26AHA26230 26A = portfolio number HA = chart series 26230 = chart number HA = harbor CO = coastal GN = general WO = world

21. Chart Ordering Can buy a portfolio Can purchase individual charts (E.g. 26A = General & Harbor charts for 26) You must have the latest, large scale chart for your location. All (or most) charts in a subregion

22. Chart Editions You must use the latest chart! Date and Edition Number are on the chart New editions issued due to many changes Current edition number – lower left 1 st Edition date – top center

23. Chart Editions

24. Chart Revisions Includes latest corrections Issued when out of stock Few, minor corrections A new edition not warranted Revision date (not number) printed near the current edition number.

25. Chart Revision Date

26. Introduction to Navigation Questions?