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Old 07-10-2007, 11:39   #31
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I learned celestial nav back at the maritime academy and still practice it when I can. How embarrassing and dangerous would it be to be "lost" on a commercial vessel if GPS went down and LORAN was not available? Keeping a DR on paper is always a good idea. How many people offshore would be totally screwed without GPS? At the very least people should know how to do a LAN to get their latitude. That is relatively easy...and fun. Those cheap plastic sextants are good enough for 5-10 miles depending on conditions. The metals ones are good roughly down to about 3 miles...depending. There are decent metal ones now under $1000 that are made in China.
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Old 07-10-2007, 20:49   #32
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At the very least people should know how to do a LAN to get their latitude.

I'm gonna learn to do that right after i learn to ride horses cause the car might break down! Seriously...there is no need for any celestial knowledge these days. Just carry a few 100 buck backups for the GPS and plenty of batteries.
Yeah...the GPS might go out...but I think the odds of Armageddon are small and somewhat more probable is bad weather or day/night cloud cover that won't let me take a sight.
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Old 08-10-2007, 05:12   #33
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Like most, I enjoy the conveniences of my nav electronics, but as a Master Mariner who used to teach both costal and celestial navigation, I worry about those who rely solely on modern navigational magic without the knowledge of how to determine if fixed or variable errors exist on those electronic aids.Electronic charts are great for route and passage planning, wonderful in a seaway when you are considering alternate weather destinations and easy to display in a wet cockpit. However Murphy’s Law does exist and they will fail at the worst time.
That is why when coasting, I still use my Radar and parallel indexing from prepared paper charts to keep my own processor working. Also as an aside, I will never allow a GPS to be tied into the autopilot so that the watch keeper has no feel for our set and drift, if all that magic fails
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Old 08-10-2007, 06:12   #34
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One of owners of where I work just bought a 23' center console for fishing in the bay, he knows I am into boats so he comes to me asking about Chartplotters and fishfinders. He wanted to get the raytheon yada yada yada. I wound up selling him a spare GPS I had, a Garmin 76. It has all the bouys and navaids in it. I told him it would be far better for him to get a seperate "fishfinder" and keep a weatherproof chart at the helm and learn to use it along with the compass and checking his position with the handheld when needed. He is only fishing local spots, its not like he will be going into strange anchorages very often. He has fallen in love with the small handheld. He also like the idea of saving some cash. And I have some fresh fish in my freezer now with more to follow. I told him the first time he finds fishing spot with the GPS and goes back to get more not to forget me with some more fresh catch.

I enjoyed some fresh grilled Bluefish last night from that GPS sale.
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Old 08-10-2007, 07:02   #35
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i sailed through png from bougainville to cairns in 95 and the gps was down for a 3 weeks we passed big ships anchored up who couldnt believe it either and im pretty sure armageddon didnt happen
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Old 08-10-2007, 07:10   #36
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I bought an old used handheld GPS for 40 bucks at a flea market not too long ago. I do plan to use it, but before I get out of local waters I plan to learn celestial navigation and get a sextant as well. The handheld doesn't even really have any bells and whistles, the only thing it's good for is giving me mat Lat and Long, and a very shaky compass direction. This makes it pretty much a requirement to use it with paper charts.
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Old 08-10-2007, 10:53   #37
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If Armageddon does happen there won't be a home to sail back to...so wouldn't it be a wise idea to know how to get to your favorite tropical isle using the stars?
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Old 09-10-2007, 10:21   #38
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bougainville to cairns in 95 and the gps was down for a 3 weeks

Would you kindly supply some proof of a 3 week outage of GPS. I think it would have made some news. In any event these were the early days of GPS and a PLANNED and ANNOUNCED maintenance event took down the system for 18 hours from what I am able to research. The entire GPS system while tested for some years only was declared fully operational in 1995 so my guess is that you were using a pre-cursor system rather than GPS.
Of course the system no longer requires this type of maintenance/outage and I can think of many passages in which 18 hour cloud cover would prevent me from navigating by celestial.

As to a sextant to find my "island" after Armageddon...there might be a problem finding any islands after to polar caps melt! (g)
Let me be clear that I can appreciate the desire to learn something like Celestial and the fun it might be to take a sight and reduce it and come out somewhere within a few miles of where the GPS says you are. Hell, some people enjoy tying flies or knitting. I am only commenting on the NEED to know Celestial in this day.
Furthermore, I am simply talking about GPS positioning...NOT chartplotters and electronic charts and auto-steering. I am totally in agreement with Pelagic about that.
I might add that in addition to many decades of sailing using traditional coastal nav tools, and self-training on a Davis sextant with a William F. Buckley tape and several "How to" books... I also have part time & full time cruised for quite a few years and never encountered a situation where my GPS did not work OR did not provide a significant improvement in positioning over what the best sextant and user could provide. (The sextant and books are in the closet for good.)
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Old 09-10-2007, 11:44   #39
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I was doing the Vanuatu to PNG to Darwin route in 1995 too, and I never had any 3 week gps black out, it may have been a specific system failure. Back in the early 90's it was often stated by various old barnacles, that to sail with GPS and no sextant, was terrible seamanship, but to sail with only a sextant was fine.
In 94 in Mexico I helped some other boats lead an exhausted single handed sailor back to the mainland after he had fallen and damaged his sextant without which he had no other form of navigational back up.
Now I recently heard a current 'expert' claim it was negligent seamanship to leave port with out a computer world tide program.
For myself when I take off again I will have a plastic sextant on board to use with my kids in pretty much the same way I'll have a book on ornamental knotwork.
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Old 09-10-2007, 21:58   #40
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No one navigational device replaces or makes completely obsolete any other navigational device. Given that, it is best to bring on board whatever is available...within reason. Obviously we are not going to be bringing out astrolabes.

When I read an article in Latitude 38 some time ago a discussion about AIS "replacing" RADAR I just had to roll my eyes. One does things the other does not therefore they complement each other making for safer navigation, not replace each other.

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Originally Posted by TAREUA View Post
Now I recently heard a current 'expert' claim it was negligent seamanship to leave port with out a computer world tide program.
Bring both...the paper in case the computer craps out and the electronic tables for the ease of use and in case the paper tables get wet or lost.

Astrolabe - Wikipedia, the free encyclopedia
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Old 10-10-2007, 08:23   #41
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as i mentioned earlier we passed a number of ships(6 to be precise) anchored up who we had radio contact with who had also had their gps go down at the same time as ours had. this didnt concern us overly much however as we were hoping that this might keep the png navy at home as we were trying to sneak out of the country as they wanted to arrest us and sink the boat. we had taken medicines to bougainville island supposedly with permission but it got revoked and we became png in png. this was arounf the end of august/ start of september
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Old 10-10-2007, 12:29   #42
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Northern Cat we got to PNG later than that in the season. We had to make a repair or two, then when we tried to leave for Indonesia and hit a submerged deadhead and broke a shaft coupling. By the time the part came the monsoon had changed and we spent the next few months there waiting out the season. It was one of the best experiences of our cruising years, but the PNG navy wanting to capture a boat for delivering medicine? That wouldn't surprise me. The government was pretty unique at the time. They were trying to span the distance between dealing with stone age tribes and modern international oil companies from a capital city whose streets only extended about 25 miles out of town.
It brings back a lot of memories, did you ever deal with the freindly port captain in Moresby who always pronounced his p's as f's and vice versa? "How do you like the fort? We must collect the fort peas."
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