Go to Starpath Home Page



How to use these data, some from databases, some from our own books of exercises, some from actual measurements of our own and our students. We have both ocean navigation, marine weather, and coastal navigation problems on all levels.

Problems include: star and planet ID, celestial fixes, ocean DR, noon sights, sights selection, sight analysis (choosing best from a series of sights), plus GMT by lunar distance and by lunar altitudes, among other things. Need your own almanac data from past dates (see Shareware and Freeware) or use online resources from Celestial Inet Connections.
Lunar Altitude example
This method is a way to find GMT from the moon using more or less normal sights and thus has an advantage over lunar distance method, which requires special sights and special sight reduction procedures. Note that both of these methods require very accurate sights and are best reduced using a calculator or PC program since multiple reductions are required with highest possible precision. You can use the sight reduction routine from the NIMA computers (decoratively called Pub 229) which you can download from the shareware section of the Library.
Real sextant sights
Discussion of sextant sights with links to Starpath articles on sight analysis, plastic sextants, reading vernier scales, and actual data of sights underway and on land... to large part motivated by a past discussion with Cruising World magazine. Sights were taken at sea and on land with both metal and plastic sextants. Plus data on measuring index correction with plastic sextants.
Ron Baker Sights
A full set of cel nav sights from Ron Baker, which can be analyzed for practice. All necessary data are included.
General navigation
Practice with DR
This pdf article covers all methods of doing numerical dead reckoning (as opposed to plotting) and provides extensive practice problems headed in all directions in all quadrants. It is useful in all phases of navigation. That is, given a Lat Lon position and a course and distance run (or speed and time run) what is your new Lat and Lon. These notes explain the best way of doing this.
Random question generator
With this function you can generate practice tests on any subject in marine navigation or weather based on the USCG License exam database. Just choose the general area (Nav rules, deck general, safety, navigation, etc) then the subject (fire extinguishers, barge lights, compass corrections, etc) and choose the number of questions 10,30, or 50. You will then be presented with the quiz to work online and after submitting, you will see the correct answers and receive your score.

If you wish to take part in this free service for WebCard holders, please post a request in one of the online discussion forums and we will unlock the service for you. If you would like longer access or support with the questions from our instructors, please sign up for any one of our online courses.