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    Re: LOP Quality
    From: Brendan Kinch
    Date: 2010 Dec 15, 12:47 -0800

    Re Message [14872] : re LOP Quality ... 15Dec'10

    Nice post Jeremy and some really good information for those not familiar with operations on a merchant vessel bridge – carried out by the single watch-keeper. Making a landfall can be a busy time especially if the coastal NavAids are not up to scratch or if you are constantly watching out for those darn fishing vessels that always seem to be where you want to go.
    You asked ‘Is this about right?’ You have pointed out quite well yourself that as many means as are practical for confirming the ships position should be used when changing navigation mode (Ocean to Coastal) and especially when changing vessel position from ocean charts to coastal charts. Don’t forget the Echo Sounder can be a great help also along certain coastlines, and this in itself can provide another LOP.
    For info – my navigating days were in the ‘70s and as far as I remember LORAN-A was around but we never had lattice charts for this.....we never had a receiver. When LORAN-C came on the scene with greater range, I recall that we had to go through a book of corrections before we could get any position. Again, as far as I remember it was long afterwards before I saw a lattice chart for this system. We did however have DECCA lattice charts for that system on the European side – a great help once we knew we had the lanes locked in correctly. Much further out to sea we used to get the DF (Direction Finder) signals but it really was such a pain to try work out a position from those stations – but it did at times give some credence to the DR (since last sights) – but nothing that I ever relied on I can assure you.
    As you sit now with ECDIS by your side – just consider how fabulous the information is to hand – especially if you have RADAR & AIS all connected in as with the most modern ones I have seen. (I still work on board various vessels – but not as ship’s crew). I read now that in the future, satellite map features will also be integrated – i.e. you will see something like a Google Earth underlay and the radar returns of the coast fitting in with the map features. I guess in the early models you may have to align the two – but I am sure even that will become automated in time.
    So exciting times still ahead for young navigators - but when the lights go out; someone can pull out the sextant and say........”Did anybody wind the chronometer?”...............but I guess you don't even have to do that anymore!


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