What happens when your navigation systems fails

[reed1v]

Originally Posted by seaward 42

yeas, you are right. I can drop dead as well or Moby dick can swallow the boat. If that's happened to your friends does not mean that everyone is moron.

And stupid people assume perfection. In 40 years of sailing all over this planet we have gone through three sextants, several chronometers, and countless destroyed charts. Your naive outlook and lack of experience can mean only one thing: you live in Ohio.

[MIRELOS]

I find it hard to believe that two boats and crews were lost, I'm sure the Navy has the best of equipment and probably redundant systems. Were the crews not well trained?.
Do they not also carry paper charts as every sailor should?. Paper charts do not fail, only the navigator can be faulted.

[JUNKFLYBOY]

Don't post much but this inspired me to ask a question on this subject.

I use a land Garmin that has walk mode to simply give me back up lat/long which can be put on paper charts. I have never had to do this but what are the pitfalls of this backup to the moving map installed in the boat??? i know nothing about sextants. Yes i can read maps!

[adlib2]

Originally Posted by JUNKFLYBOY

Don't post much but this inspired me to ask a question on this subject.

I use a land Garmin that has walk mode to simply give me back up lat/long which can be put on paper charts. I have never had to do this but what are the pitfalls of this backup to the moving map installed in the boat??? i know nothing about sextants. Yes i can read maps!

I don't see any pitfalls. When serious passage making I always plot my position on a paper chart every hour or so. I started sailing long before GPS and paper charts became a habit which I continue for the simple reason you have a better view of where you are and if you do lose your chart plotter you have a good starting point for dead reckoning.
I do carry a Freiberger Sextant and navigated all around the Caribbean with it at one time and do hold a certificate for CelNav so could use it again if necessary.

[TrentePieds]

Quote: "I use a land Garmin that has walk mode to simply give me back up lat/long which can be put on paper charts. I have never had to do this but what are the pitfalls of this backup to the moving map installed in the boat??? i know nothing about sextants. Yes i can read maps!"


Uhm... With respect: I think you have it bassackwards. Your coordinates, however you get them RELIABLY - sextant or GPS reading, are NOT "backup" for your chart plotter. They are your PRINCIPAL data. It's the chart plotter that is your "back-up". And a decided convenience provided you've got the other stuff right :-).

I find that using my retrofit GPS from the car, set to display the co-ordinates directly, permits me to plot my position on a paper chart in less than 2 minutes, and to keep the last plotted co-ordinates fresh in my mind. In practice what I do is that I read the GPS, write up the log (takes 15 seconds), then plot "at convenience". "At convenience" is usually "right now", but there are times when other things may take precedence. To go back and plot on the chart ten minutes later is no problem cos the coordinates are already, permanently, in the log. I don't usually bother with the chart plotter.

TrentePieds

[hamburking]

Originally Posted by JUNKFLYBOY

Don't post much but this inspired me to ask a question on this subject.

I use a land Garmin that has walk mode to simply give me back up lat/long which can be put on paper charts. I have never had to do this but what are the pitfalls of this backup to the moving map installed in the boat??? i know nothing about sextants. Yes i can read maps!

I think if you really were familiar with "maps" you might have called them "charts".

I use (a pair) of garmin etrex as backup, and sometimes as primary. Yes, they give you your position, but navigation is quite a bit more than just figuring out where you are...there is also the question of where you are going! And this takes practice.

For example, I enter a waypoint for a known hazard, like a shoal or rock I want to avoid. Then I can "GOTO" that waypoint to instantly know its bearing and distance. Sounds simple, yes, but if not thought of beforehand, can be a problem, especially if the waves are high and the wind is strong.

This summer I delivered a sailboat from Brockville to Toronto. The owner had purchased an ipad and navionics as the primary nav system. Unfortunately, the dollar store/canadian tire charger was not the high current type needed for an ipad, but rather a low current version suitable for an iphone. So yes, the ipad quickly ran out of power, for the sake of an inexpensive component. I had asked the owner to purchase "Richardson's", a chart book for Lake Ontario, but he didn't get over the sticker shock in time, so that was also missing. The previous owner assured us he would leave some charts aboard, which turned out to be screengrabs, printed on a inkjet printer...not much more than thumbnail images. Fortunately, I had brought my etrex and some (very old) paper charts. I was also pretty experienced at that particular trip, so was able to do most of the trip by memory. In that case, we were lucky, but the etrex became the primary nav device. In the hands of the boat owner, it was almost useless. Like anything else on the boat, you've not only got to know how to use it, but have some experience with it as well. When the time comes that you need it, there will likely be other issues to deal with, like wind and waves at the very least.