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What Sextant are you using onboard?

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  • What Sextant are you using onboard?

    I'm doing an article for my blog, and would like to ask some help from Cadets and Officers who presently onboard ships. Please could you let me know what sextants you have onboard, what the make and model is, what date is was manufactured and when it was last inspected ashore. Also, if you know how to determine the index error, I would be interested in that too.

    Thanks in advance.

    Date of Manufacture:
    Last Inspection date:
    Index Error:

  • #2
    No Sextant.

    It's the 21st century dude.


    • #3
      Really? Do you operate deep sea? What mathod of navigation do you have other then GPS? Do you appreciate the limitations of GPS?


      • #4
        Most of the ships I've sailed on haven't carried sextants... work offshore in the north sea so your lucky to see the sun or a star in a trip... but on most the ships i was on deep sea we never carried sextants... Fully aware of the fallibility of the GPS, I've seen it dance around giving crazy positions on several occasions. also the officers I did my training with also never once used a radar range and baring whilst on a repeated voyages from the south of Italy all the way down to the bight of Benin... even whilst on coastal navigation we had many good radar targets were available on the coast it was always done via GPS right the way up to the berth.... scary stuff eh??... no doubt we will have many more "Rena's" in the years to come.

        Same officers I did my training with also taught me to use the AIS information for your CPA and collision avoidance over radar ARPA... Whilst a cadet I didn't know any better but you soon learn how dangerous this practice is... Makes you wonder what kind of folk are navigating ships out there...


        • #5
          I can fully appreciate the lack of sextant on a vessel operating primarily off the coast and if your operating DP you probably do have a good understanding of the limitations of GPS, however deep sea officers without a doubt must be competent in celestial.

          Being a competent navigator includes many aspects, whether its understanding and using the CATZOC data on Electronic Charts to plan routes effectively ( or even HORACC, POSACC, SOUACC, VERACC, SURATH, SURSTA, QUASOU, QUAPOS, TECSOU data), understanding what equipment is linked to the emergency power, what equipment you lose if the gyro fails and what equipment you lose if the GPS signals is lost, clearing bearings, parallel indexing, fixing by visual references etc, these are all things that professional navigators should know, without them you are not much more use then a bus driver on the bridge.

          When operating on a deep sea passage, if there are GPS signal failures or jamming (occurs more frequently then people assume), you must be prepared to D.R properly and then fix by other means (i.e. celestial). I know that where I work now, and in my previous companies, they'd be very dissapointed if we did have a GPS failure and told them we couldn't continue....


          • #6
            To answer the original question, onboard we had;

            Make: Freiberger Prazisionmechanik
            Model: Frommel
            Date of Manufacture: Unknown (probably around date of Inspection)
            Last Inspection date (Shoreside): 12 April 1973
            Index Error: 0 (at inspection date - presently zero as well)
            ?Twenty years from now you will be more disappointed by the things you didn?t do than by the ones you did do. So throw off the bowlines, sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.?

            ? Mark Twain
            myBlog | @alistairuk | flickr | youtube Views and opinions expressed are those of myself and not representative of any employer or other associated party.


            • #7
              Thanks Alistair, Frieberger Drum Sextant is quite a good sextant, easy to use.


              • #8
                Ancientmariner is right. Sea going ships nowdays, especially merchant vessels are equipped with sextant, it's one of the oldest navigational tool and it helped seafarers many hundred years.
                It's not about where you are from, it's all about where you are going.


                • #9
                  Make: Tamaya
                  Model: Not sure of which model hadn't seen this thread when I was on board
                  Date of Manufacture: Sometime in 1997
                  Last Inspection date: can't remember the exact date but was shortly after the date of manufacture
                  Index Error: was 0 at last inspection but is currently 1.0' on the arc

                  Also my opinion on astro is that it is an important skill to learn and you never know when it might come in useful, even if it is just to give officers something to do on deep sea bridge watches after all there isn't any thing else to do.