Celestial Navigation


ASA107 Course Materials

ASA107 Celestial Navigation Sandards

1. Celestial Navigation for Sailors text; 252 pages; Dec 2013 edition. 
Purchase item 21

2. Solutions for Celestial Navigation for Sailors workbook; 134 pages; Dec 2013 edition.  
Purchase item 22

3. Star Finder 2102D Circular Slide Rule. Purchase item 23

4. NGA 925 Position Plotting Sheet; 35 x 45 inch chart. 
Purchase item 25

5. Homework Plotting Sheets. Download PDF

6. HO229 Sight Reduction Tables, Volume 3; purchase from Amazon or others. 
Download PDF

Errata for books 1 & 2- Download PDF




Instructor Teaching Guide

by Tom Tursi

The ASA107 Celestial Navigation Course uses the items shown above. These materials should be provided to students in advance of class to permit study prior to coming to class. Ask students to read at least Chapter 1 in the Celestial Navigation for Sailors text, and to attempt to do the Chapter 1 homework prior to the first class day.  

Students will need one copy of the NGA 925 position plotting sheet during class to complete homework assignments and a second copy when taking the ASA107 exam. The Homework Plotting Sheets shown above can be used for some of the homework assignments, but cannot be used for the exam.

Appendix L provides answers to all homework questions in the Celestial Navigation for Sailors text, and the Solutions to Celestial Navigation for Sailors workbook gives step-by-step solutions to all of these questions.

For classroom instruction, I suggest that projection images be prepared from the figures in the textbook. It's also helpful to hand-draw some images on a flip chart during class to help students follow the more difficult procedures. 

I suggest that instructors require students to hand in homework assignments for review and coaching. Otherwise, some students fall behind and hesitate to ask questions. 

Also, show in class examples of actual items such as navigational charts, plotting tools and publications. If extra copies of charts and pubs are available, pass them around and make them available for student perusal during class breaks.  

Students need adequate time between classroom sessions to do homework and practical exercises. I suggest scheduling class day #1, followed by a two-week gap, then class day #2, a two-week gap, and then class day #3. These should be full 7-hour class days each.    

An alterative to this schedule, is to hold six half-day sessions with adequate time between for students to complete homework and practical exercises, plus the final exam day as discussed below.   

Here is how I conduct the four-day course:

Day 1 Teach Chapter 1 and do the Practical Exercises with class participation; review the Chapter 1 Homework assignment; and assign the Chapter 1 Homework for completion and submittal prior to next class session.
Day 2 Review Chapter 1 Homework; teach Chapters 2 and 4 lessons and do Practical Exercises with class participation; assign the Chapters 2 and 4 Homework for completion and submittal prior to next class session.
Day 3 Review Chapters 2 and 4 Homework; teach Chapter 3 lessons; and assign the Chapter 3 Homework for completion and submittal prior to next class session.
Day 4 Review and answer questions. Begin written exam by the end of first hour of class.

Day #4 (exam day) is for final review of key topics, answering of last minute questions, and for the ASA107 written exam. I have found that student take from three to six hours to complete the exam, and instructors should plan the timing of this day to allow students adequate time to complete the exam. After grading the exams, instructors should critique each student on the results of the exam, whether this is done on the same day or at a later time.

The NGA 925 plotting sheet is mandatory for use in the exam. The commonly used Universal Plotting Sheet will not work and cannot be used for the exam, and students and schools need to know this up front. 

The NGA 925 plotting sheet can be ordered directly from Ocean Grafix Print on Demand at http://www.oceangrafix.com/chart/detail/925-Plotting-Chart-925  We provide this plotting sheet to students for the exam.

The HO229 Volume 3 Sight Reduction Tables for Latitudes 30 to 45 may be needed during the exam if the student has made a slight calculation error that places them off of the HO229 extract pages included in the exam booklet. In this case, without the full volume available, the student will be stopped and not able to complete the exam. So, I always make the full HO229 Volume 3 available during the exam in case they need it. Schools can readily obtain this volume from Amazon and others, or can download the PDF file.
The exam lists the correct GMT times needed for the five sight reduction calculations in the exam. It provides shot times as Eastern Daylight Time and students need to convert these to GMT for the sight reduction calculations. If they make an error when converting EDT to GMT, they will be unable to complete the remainder of the exam. So, I have found it desirable to give them the GMT times, and instruct them use these GMT times for their sight reduction calculations even if they are unable to successfully convert EDT to these GMT times. Schools and students need to understand this up front.

I welcome and encourage instructor feedback, comments and suggestions on any aspect of this program in the interest of improving and making it more useful to both students and instructors.  

Good Sailing! 
Tom Tursi 



Some References from the Internet


NOAA (National  Oceanic & Atmospheric  Administration)

-Weather  Fax
-Hurricane Tracking
-Weather Text
-Chart numbers &  titles
-Chart Viewer
-Chart Catalogs
-Tide Predictions
-Current Predictions
-Ports Real Time System
-Chart Sources
-NAVTEX Schedule

NGA (National  Geospatial-Intelligence Agency) 

-USCG Light List Database 

-NGA List of Lights Database

-Ocean Pilot Charts
-Magnetic Variation
-Navigational Warnings
-Anti Shipping Activity  Messages
-Mobil Offshore Drilling Units
-Nautical Almanac
-HO229 Sight Reduction Tables


US  Coast Guard 

-USCG Light List Download
-Navigation Rules Download
-COLREGS Demarcation Lines
-Notices to Mariners
-GPS Info
-VHF Frequencies

Other  Sources:

-Radio Technical  Commission for Maritime Service
-Cloud Types