1. Grunt Productions 2007
Introduction toIntroduction to
Astro-NavigationAstro-Navigation
(Why bother with Astro?)(Why bother with Astro?)
A brief by Lance GrindleyA brief by Lance Grindley

2. Grunt Productions 2007
Is this a necessary skill?Is this a necessary skill?
 GPS and GLONAS are the only world-GPS and GLONAS are the only world-
wide navigation aids, at the moment.wide navigation aids, at the moment.
 Most ships have a single GPS receiverMost ships have a single GPS receiver
 GPS is relatively easy to jamGPS is relatively easy to jam
 High mountains may create shadowHigh mountains may create shadow
zones for low satelliteszones for low satellites
 Astro-navigation still regarded as aAstro-navigation still regarded as a
professional skill by marinersprofessional skill by mariners

3. Grunt Productions 2007
Navigation Watch CertificateNavigation Watch Certificate
 Astro NavigationAstro Navigation The STCW code requiresThe STCW code requires
that any officer in charge of a navigationalthat any officer in charge of a navigational
watch shall have the ability to use ‘celestialwatch shall have the ability to use ‘celestial
bodies to determine ship’s position’.bodies to determine ship’s position’.
 Formal instruction in techniquesFormal instruction in techniques
 Practical trainingPractical training
 Examination in astro-navigation andExamination in astro-navigation and
calculation of ephemeral data.calculation of ephemeral data.

4. Grunt Productions 2007
Old Attitudes (Not very PC!)Old Attitudes (Not very PC!)
 Merchant Naval officers are seamenMerchant Naval officers are seamen
pretending to be gentlemen.pretending to be gentlemen.
 Do you want to be regarded as aDo you want to be regarded as a
professional seaman and watch keepingprofessional seaman and watch keeping
officer?officer?

5. Grunt Productions 2007
Astro-NavigationAstro-Navigation
Fixing usingFixing using
the starsthe stars
ProfessionallyProfessionally
satisfyingsatisfying
A recognisedA recognised
professionalprofessional
skillskill
OccasionallyOccasionally
very necessaryvery necessary
Qualification forQualification for
RYA offshoreRYA offshore
skipperskipper

6. Grunt Productions 2007
The Main RequirementsThe Main Requirements
 Look at the concept of the celestial sphere.Look at the concept of the celestial sphere.
 Explain the importance of time and hour angle.Explain the importance of time and hour angle.
 Identification and selection of stars and planets.Identification and selection of stars and planets.
 Explain the principles of Marcq St Hilaire'sExplain the principles of Marcq St Hilaire's
method of finding your position.method of finding your position.
 Practical work on Astro.Practical work on Astro.
 Plotting position lines.Plotting position lines.
 Practical work to collate all the information.Practical work to collate all the information.

7. Grunt Productions 2007
The Main RequirementsThe Main Requirements
 Look at the concept of the celestial sphere.Look at the concept of the celestial sphere.
 Explain the importance of time and hour angle.Explain the importance of time and hour angle.
 Identification and selection of stars and planets.Identification and selection of stars and planets.
 Explain the principles of Marcq St Hilaire'sExplain the principles of Marcq St Hilaire's
method of finding your position.method of finding your position.
 Practical work on Astro.Practical work on Astro.
 Plotting position lines.Plotting position lines.
 Practical work to collate all the information.Practical work to collate all the information.