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Showing posts from February, 2022

ASA 105 Study Guide

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ASA courses are taught only at ASA schools.   Follow along with an ASA 105 Coastal Navigation lecture.  You will need navigation tools and a copy of the training chart 1210 TR and a copy of the current edition of Eldridge Tide and Pilot .  This work is based on lecture notes of the author an ASA Instructor Evaluator.  This study guide is designed to help prepare students for the class work and ASA 105 test. Students are encouraged to gain experience underway as well as in the classroom.   The author recommends that students own several books in addition to the prescribed teaching materials.  The first book is essential to the course.  The others are a logical addition to any navigator's bookshelf.     1. Eldridge  Tide and Pilot 2022 .  This book is essential for cruising the US East Coast and New England in particular.  It contains hourly current vector charts and coastal piloting tips not easily found elsewhere. ...

ASA 105: Skill 1, Chart symbols

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  1.   Explain the chart symbols and conventions on U.S. nautical charts in accordance with the terminology of Chart #1. Charts are comprehensive presentations of knowledge required by maritime navigators.  One must be able to intemperate the symbols.   Chart One is the most thorough. Chart One shows chart symbols and explains the meaning of each.  An abbreviated copy is printed on the back of Chart 1210Tr.  We focus on USA symbols which are also common to most maritime charts.  Chart One may be purchased from maritime publishers and/or downloaded to a computer or smart phone.  A link to one source follows. https://nauticalcharts.noaa.gov/publications/docs/us-chart-1/ChartNo1.pdf Nigel Calder's book:  How to Read a Nautical Chart  is an excellent reference as it provides additional commentary about symbols and their relevance and limitations. Chart One, front and back Nigel Calder's book cover

ASA 105: Skill 2, Locating resources

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  2. Identify a source of official U.S. Coast Guard navigation publications. Companies such as Landfall Navigation, Paradise Cay Publications, International Marine, and OceanGrafix supply many printed US Government authorized maritime publications.  These include Light Lists, Tide Tables, NOAA charts, and Coast Pilots.  Links follow. https://www.mhprofessional.com/international-marine https://www.landfallnavigation.com/navigation/navigation-books-guides.html https://www.paracay.com/nautical-charts-and-books https://www.amnautical.com/pages/u-s-government-publications https://www.oceangrafix.com/products/coast-pilot https://www.oceangrafix.com/products/light-list https://www.oceangrafix.com/products/tide-tables Unofficial resources are cruising guides and  Eldridge Tide and Pilot   which has very detailed information about the US East Coast.  The book is updated each year.

ASA 105: Skill 3, Navigator publications

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  3. List the publications required for prudent navigation in the local area including: Large scale charts of the area and Chart #1 https://charts.noaa.gov/InteractiveCatalog/nrnc.shtml Federal Requirements for Recreational Boats 4 20.PDF (uscgboating.org) USCG Navigation Rules and Regulations Handbook https://www.paracay.com/navigation-rules-and-regulations-handbook/ State small vessel regulations, Rhode Island's for example rhodeisland-handbook-entire.pdf (kalkomey.com) Local rules and regulations, if applicable Harbormaster office Local cruising guides Local marine store or online Tide and current tables, (paper or electronic) Eldridge Tide and Pilot available local marine stores Paradise Cay Publishing  List of lights, buoys, and fog signals Eldridge Tide and Pilot available local marine stores Paradise Cay Publishing  Resources are available from a variety of sources.  We offer sample selections above.  Old book stores often turn up out of print books that ...

ASA 105: Skill 4, Navigation tools and instruments

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  4. Describe the instruments required for prudent navigation in the local area including the following minimum requirements: Steering compass and deviation table Hand bearing compass and / or pelorus Binoculars Protractor or parallel rule Depth sounder or leadline Pencil, eraser, and notebook Dividers Watch or clock Log / Knot meter Add to the list:     VHF radio.  Listening to VHF Channel 16 alerts navigators to emergencies, local hazards to navigation, and weather anomalies.  The USCG broadcasts such notices on VHF Channel 22 after announcing the alert on VHF Ch 16. VHF WX channels provide current weather information and warnings needed by the prudent navigator. Magnifying glass.  

ASA 105: Skill 5, Notice to Mariners

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  5. Describe the purpose and example contents of a “Notice to Mariners.” The Notice to Mariners is an official document that reports changes to aids to navigation and/or hazards to navigation.   Immediate changes are broadcast on VHF channel 22 after an alert on VHF channel 16 A link to the online Notice to Mariners pages. https://www.dco.uscg.mil/Featured-Content/Mariners/Local-Notice-to-Mariners-LNMs/ The sequence shows a 35 foot catamaran negotiating Chatham North Cut.  The channel shifts often and the skipper consulted tide tables, weather conditions, the Chatham Harbor Master and Notice to Mariners before entering. Success is planned!

ASA 105: Skill 6, Aids to Navigation, Lighted marks

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  6. Explain the terms and characteristics used for lighted navigation aids. Lighted aids to navigation are necessary for night navigation.  The light colors are specific to maritime use and the lights have distinctive characteristics such as frequency of flash.  There are some fixed (not flashing) lighted aids to navigation but not many.  Sandy Hook Light at the entrance to NY Harbor is one.  Others are Hospital Point Light in Salem Harbor and nearby Marblehead Light (fixed green).  Those are the only three seen by the author. Nobska Light, Massachusetts This light can be found on chart 1210Tr near Woods Hole.  It is a classic structure with white buildings and red roofs.  The lighthouse itself is a simple tubular building surmounted by the light enclosed in the black ironwork. Dutch Island Light, Rhode Island This lighthouse is located on Dutch Island at the western side of Conanicut Island.  Its location can be found on chart 1210Tr. ...

ASA 105: Skill 7, Aids to Navigation, Unlighted marks

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7. Explain the significance of shapes, colors, and lights used in the U.S. Aids to Navigation (ATON) system. Nun buoy Conical top is a requirement for nun buoys.  If marking a channel they have even numbers are red in color and are left to starboard when entering, port when departing. Ready references include: Chart One , Page 125  Eldridge 2022,  Page 214 Boat Navigation for the Rest of Us, inside flaps and back cover Shapes and colors are important for day piloting.  Lights on buoys are often correlated to the color of the buoy itself. Nuns have conical tops.  Red nuns with even numbers are lateral marks denoting the left side of the channel when heading seaward.  Nuns are not lighted. Cans have cylindrical tops.  Green cans with odd numbers denote the right side of the channel when proceeding seaward.  Cans are not lighted. Tower buoys may have a sound signal or a light or both.  The color denotes the buoy's significance.  Red or Gree...

ASA 105: Skill 8, Tide and Current

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  8. Use the tide and current tables to find: Times and heights of tides at reference and secondary ports. Direction and rate of current at referenced and secondary stations. Tide is the vertical movement of water.  Current is the horizontal movement of water.  The two are related.  On the US East Coast the tidal cycle is diurnal with high tides occurring about every 12 1/2 to13 hours.  Refer to Eldridge 2022 Newport pages and note that high or low tides are a little later every day.   The tidal range varies as well.  Time of high or low water and tidal range are not the same everywhere.  Refer to the Boston pages, for example, to see that the time of high water is three hours later than at Newport and the range is 9.5 ft. Boston and Newport are among the list of primary tidal stations.  Secondary stations are noted separately on pages 12 through 20.  Page 15 shows the time of high water at secondary stations located on chart 1210 ...

ASA 105: Skill 9, Measurements

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  9. Measurements:  Convert courses and bearings between true, magnetic, and compass.  Determine Latitude and Longitude.  Measure distance. Nautical measurements on a chart are either Angular or Linear .  Courses are angles and distances are linear.  The other vital nautical measurement is Time given in hours and minutes. Leading lights, such as this pair in Nantucket, are a guide for staying in the channel.  They may be used to check you compass deviation.  In that instance we use a line, the range, to correct an angle, compass deviation. The first measurement for navigators is True North.  The longitude lines on the chart are North/South lines.  The North Pole is an absolute.  Compasses, however, don't point at the North Pole, they point at the Magnetic Pole which shifts ever so slightly each year.  The inner rose of the compass rose printed o a chart represents the Magnetic Pole and shows the Variation from True North. Com...

ASA 105: Skill 10, Calculating Deviation

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  10. Check compass deviation by a transit bearing or other means. Compass deviation is how we address the magnetic field of a vessel.  Deviation may change over time as the magnetic field of the yacht changes.  This is more common for steel or wooden hulls fastened with iron than for fiberglass yachts.   There are two basic ways to check deviation.  The first and oldest is by using a table of the sun's true bearing at sunrise and sunset for a given latitude.  The other is by using a charted range (transit bearing).  We will look at the range method. Nantucket Harbor Channel Range This is similar to the range used in the example, Cleveland Ledge Channel Range. The yacht should move right to get the ranges aligned The TVMDC AW formula is used.  When D is unknown, the arithmetic result is D using TVMDC.  In such a case, TVM and C are knowns so we solve for D. Turning to Chart 1210 Tr, observe the charted "Cleveland Ledge Channel" range for...

ASA 105, Skill 11, Ded Reckoning (DR)

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  11. Plot a dead reckoning position on a chart using speed, time and course to steer. Deduced Reckoning or Ded Reckoning or DR ("dead" is a common misnomer) is based only on two factors:  speed and direction.  No outside influences are considered. For example:  If you proceed due North at 6 knots in one hour your DR position is 6 nautical miles due North of the starting point. Use Chart 1210Tr for this exercise.   Make a DR plot of three legs from Cleveland Ledge Light to Lone Rock at Quick's Hole, transit Quick's Hole, and finish at the entrance buoy for Menemsha Harbor, Bell "1." Assume a speed over ground of 6 knots. Mark of course Heading to next Distance to next Time to next R "14" Fl R 2.5 sec 215 deg T 12.2 nm 2 hrs 2 min BR Qk Fl G 167 deg T 2 nm 20 min G "1" Fl G 4 sec Bell 143 deg T 5.3 nm 53 min "1" Bell 19.5 nm 3h 15 m in transit Your DR plan looks something like this.  Knowing one's departure time one can estim...