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LESSON 3: NAVIGATIONAL PUBS AND BASIC PLOTTING. 1/4/2020. Lesson 3: Navigational Pubs and Basic Plotting. AGENDA: Navigator’s Reference Publications Publication Correction System Chart Symbology Basic Plotting Techniques Applicable reading: Hobbs, pp. 57-78.
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Lesson 3: Navigational Pubs and Basic Plotting • AGENDA: • Navigator’s Reference Publications • Publication Correction System • Chart Symbology • Basic Plotting Techniques • Applicable reading: Hobbs, pp. 57-78.
NIMA Catalogue of Maps, Charts, and Related Products • Illustrated catalog of maps, charts, publications, and other related products produced by NIMA. • Contains serialized drawings of the world which allow the navigator to locate charts and Sailing Directions that cover areas of interest. • Published as an eleven volume set.
Use of the NIMA Catalogue • A navigator is planning to enter Rio de Janeiro, Brazil. • Step One: Review the index of the world’s coastal regions/subregions. Rio de Janeiro is on the eastern coast of South America and lies in Region 2.
NOS Nautical Chart Catalogue • Set of drawings, very similar to those found in the DMA catalog. • Cover U.S. waters
Coast Pilots • Provide supplemental information about navigation in U.S. coastal waters. • Information includes: • topographical features • navigation aids • normal local weather conditions • recommended tracks • pilot information • descriptions of ports and harbors
Sailing Directions • Provide supplemental information about navigation in foreign coastal waters. • Information provided is similar to that found in Coast Pilots. • Divided into different volumes • 8 volumes are Planning Guides for ocean basin transits • 35 are Enroute Directions for piloting in coastal waters.
Fleet Guides • Provide information for use by U.S. Navy ships, including: • command information • navigational information • logistics • port operations • repair facilities • Fleet Guides exist for ports frequently visited by the U.S. Navy in both the U.S. and foreign countries.
Light List • Lists aids to navigation in U.S. waters, including: • lighted aids to navigation • unlighted buoys • daybeacons • fog signals • radiobeacons • Loran-C coverage
List of Lights • Describes aids to navigation found in foreign waters and selected U.S. coastal regions. • Similar to Light List but does not contain information on unlighted navigation aids.
Pilot Charts • Name is misleading- they really cover major ocean basins and not piloting (coastal) waters. • Provide meteorological, hydrographic, and navigational information for a particular ocean area. • Extremely valuable in voyage planning.
Publication Correction System • Corrections to publications are disseminated via Notice to Mariners and Local Notice to Mariners. • Notice to Mariners - issued by NIMA and contain changes relating to oceanic and coastal areas worldwide. • Navigators are not required to immediately enter changes in every publication. • Publications are updated on the occasion of their use.
Distances Between Ports (Pub 151) • Lists great circle distances among the most frequently traveled sea routes throughout the world.
Plotting a Position • Determine the parallels on the chart that bracket the latitude. • Place the pivot point of the compass on the closest line. • Spread the compass until the lead rests on the given latitude. • Move to the approximate longitude and swing an arc.
Plotting a Position • The same process is repeated using the longitude scale and the given longitude. • The desired position is the intersection of these two arcs. • If plotted correctly, the intersection should occur at the crest of both arcs.
Measuring Distance • The latitude scale can be used to measure distances, since one degree of latitude equals 60 nautical miles, everywhere on the earth.
Measuring Direction • 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.
Hazard and Depth Symbology • Symbols are also used to denote specific hazards to navigation, such as partially submerged wrecks, etc. • Chart Number 1 is the reference for all chart symbology.