GPS system global failure

[Montemar]

What is the likelihood of the GPS system failing?
I am currently dayskippering and wonder just how necessary some of this charting stuff really is bearing in mind that the US relies on the GPS system and they aren't going to let it fail.
As regards onboard failures I have chartplotter, laptops, ipads, iphones, GPS handset, spare batteries, torch, magnetic compass and a fluxgate compass.
Oh, and a chart.
Or is it just me and I am not living in the real world after all?

 

[rafiki_]

What is the likelihood of the GPS system failing?
I am currently dayskippering and wonder just how necessary some of this charting stuff really is bearing in mind that the US relies on the GPS system and they aren't going to let it fail.
As regards onboard failures I have chartplotter, laptops, ipads, iphones, GPS handset, spare batteries, torch, magnetic compass and a fluxgate compass.
Oh, and a chart.
Or is it just me and I am not living in the real world after all?

I think it is good practice to have the passage planned on the chart as back up, and if on a long haul, track progress on the chart.

 

[rubberduck]

We had plotter failure a couple of years ago coming back to Fambride on the river Crouch from a couple of weeks up the Thames. Plotter went under QE2 bridge, back up plotter failed as well, then around Tilbury got a piece of fishing net round one of the props, coming round from the Thames & down the crouch was fun on an I phone & paper chart with little water due to the delay running on one prop had caused.

 

[sarabande]

I think the probability of failure is very low, but the possibility of it being switched off as part of military action is quite high.

Your DS instructors should be emphasising the need to transfer any electronic positions to paper on a regular basis, and you as skipper will need to determine that time interval. That responsibility goes with the hat.

You might also think it prudent to forestall any criticism or action from an insurance company or regulatory authority such as MCA if you were to suddenly find yourself out of sight of land having lost your electronic position, and being unable to make a landfall safely, albeit slowly. Practising survival navigation and skippering techniques should part of your personal resilience philosophy. You are heir to a thousand years of seafaring without satellites and radio; it can be done but it's a mindset far from just pressing an ON button.

De'd reckoning is not an art; it is a simple and repetitive set of minor mathematical and secretarial procedures.

 

[Robin]

Understanding the very basics of navigation techniques is IMO essential in order to get the best out of modern electronics, quite apart from any apocalyptical paranoia. Space invaders style Iphonery navigation is best reserved for armchair use I think unless the whole principle is fully understood but if it is then the gadgetry is very good and releases time to smell the roses and avoid nasties along the way. I really enjoy my modern stuff too but do so with the ingrained knowledge of how and why and the ability to question it when it tells me 2 +2 is 7 and not 4

Dinosaur 1

 

[Sticky Fingers]

Failure of GPS itself is unlikely but possible;
Failure of, or loss of electrical power to, your instruments is much more likely.

So IMHO learning at least enough chartwork to keep you, your crew, and others safe is a good investment.

 

[rosssavage]

I make very few tidal passages, and always within sight of land. I have three independent GPS systems, not including phone and iPad.

I still plot the course on a paper chart, with, at the minimum, course to steer and distance for each leg written on it.

I mentally check off each waypoint, speed made good and time the waypoint was reached.

I so, so don't need to do it, but why not? Good practice if nothing else!!!

 

[pmagowan]

With European satellites going up to provide a 'second GPS' system there will be good redundancy. I suspect that black spots will only occur during joint military exercises or in the unlikely event of a significant coronal mass ejection from the sun.

Still, best to have backups anyway.

 

[Dick Atcherley]

Aviation NOTAM's (notices to airmen) occasionally carry warnings about UK military GPS jamming exercises in one corner of the country or the other, so having a navigational plan 'b' is a very good idea indeed. In addition, I have also experienced my handheld GPS being zapped out by proximity to a powerful radar unit (in an aircraft at Cherbourg airport); the hardwired installed GPS Nav/Com was unaffected. When I asked Garmin why that was, they said that in all likelihood it was a difference in ariel - the handheld ariel faced in all manner of directions, whereas the hardwired unit was on the roof of the aircraft and pointed upwards only.

 

[Andy Bav]

Aviation NOTAM's (notices to airmen) occasionally carry warnings about UK military GPS jamming exercises in one corner of the country or the other, so having a navigational plan 'b' is a very good idea indeed. In addition, I have also experienced my handheld GPS being zapped out by proximity to a powerful radar unit (in an aircraft at Cherbourg airport); the hardwired installed GPS Nav/Com was unaffected. When I asked Garmin why that was, they said that in all likelihood it was a difference in ariel - the handheld ariel faced in all manner of directions, whereas the hardwired unit was on the roof of the aircraft and pointed upwards only.

That's interesting, when we drive past RNAS Yeovilton returning from the West, usually on a Sunday night, 7 out of the last 10 has seen something "killing" our in built GPS to an extent that it looks as though the unit is faulty, but it also shuts all systems down including aircon etc. Never touched our Tom Tom. It comes back after the Sparkford roundabout.

So I guess ours and your experience highlights just how sensitive this kit is to "something" that we cant see, but at least on land we have signposts :encouragement:

 

[TQA]

Remember when looking at anything electronic it is not IF it will fail it is WHEN it will fail.

 

[Kawasaki]

Remember when looking at anything electronic it is not IF it will fail it is WHEN it will fail.

Exactly TQA, just like your lappy or computer. Plus Chaps make sure your nav system is compatible with your Admiralty or Imray charts or whatever. There is more than one system out there. Check your paper chart. Somewhere it might say 'WGS 1984' or Similar, check what that means! Else you could be in Tesco or the Chandlery or your Berth!

 

[neiloakley]

I think the probability of failure is very low, but the possibility of it being switched off as part of military action is quite high.

I would disagree. Because of the global dependency on GPS, the US would not easily decide to implement what they call "selected availability". This is where they were able to degrade the public performance in a particular area for whatever reason. The last time it was in force was in the Gulf War at times when cruise missles were being launched. Nowadays most weapons use internal inertial navigation (at least for the final stage of flight) that is not reliant on any external infrastructure.

The latest GPS satellites (GPS 3) don't' even have the selected availability feature built in. The US simply don't need it anymore as it doesn't give them an edge when other missile navigation systems are just as accurate.

http://georgewbush-whitehouse.archives.gov/news/releases/2007/09/20070918-2.html

So, given most plotters now use GPS and GLONASS, I would only every worry about failure of power to the unit. iPad with charts is my primary backup, paper is tertiary. In familiar water I tend not to record anything on paper.

 

[prv]

So, given most plotters now use GPS and GLONASS, I would only every worry about failure of power to the unit

I don't worry about that at all.

Ariam has four GPS receivers plumbed in as part of the boat systems (Seatalk, a standalone plotter, the VHF/AIS, and an old Garmin used with the Yeoman). The boat's electrics are all brand new and fitted by me, the batteries weigh more than I do and rarely dip below 80% charge. But if there were some systemic problem, I also have a spare handheld GPS in a sealed metal tin along with two dozen sealed in-date batteries, and another handheld and pack of batteries in the liferaft grab bag. On top of that there is a smartphone per person on board, and quite often an iPad or two as well, all with GPS and GLONASS. About half the phones and tablets have full nautical charting apps as well as just GPS. It's hard to conceive of a situation in which all of these are simultaneously rendered unusable yet navigating the boat still matters.

Far more likely is some local disturbance, whether deliberate jamming or accidental interference, to the very weak radio signals from the satellites. My understanding is that GLONASS is similar enough to GPS that it would be affected along with it.

I agree that the US deliberately turning off GPS over Europe (as opposed to over, say, Syria) is very unlikely. Far, far more stuff depends on it now than did a quarter-century ago in the Gulf War. High-speed financial trading uses it for a time signal, trains use it to decide whether they should allow the doors to open, ships and aircraft have come to rely on it. A deliberate switch off is not impossible, but it's not something I worry about.

Pete

 

[johndove]

Big flash of lightning? Maybe a spare gps in a tin might work? But every gps, phone onboard would be dead.

Also a large solar flare could knock the system in the sky out. That came from the U.S. Coastguard when talk about removing sextents from merchant navy training.

 

[prv]

Big flash of lightning? Maybe a spare gps in a tin might work?

That's exactly why I have a spare GPS in a tin

Pete

 

[vas]

Big flash of lightning? Maybe a spare gps in a tin might work? But every gps, phone onboard would be dead.

not disputing what you say, but are we sure that this is the case, or is that an urban myth?
Yes, I understand if boat is hit by lightning many nasty things will happen, but a flash of lightning somewhere around say 300metres + would it affect ?

cheers

V.

 

[gjgm]

I don't worry about that at all.

Ariam has four GPS receivers plumbed in as part of the boat systems (Seatalk, a standalone plotter, the VHF/AIS, and an old Garmin used with the Yeoman). The boat's electrics are all brand new and fitted by me, the batteries weigh more than I do and rarely dip below 80% charge. But if there were some systemic problem, I also have a spare handheld GPS in a sealed metal tin along with two dozen sealed in-date batteries, and another handheld and pack of batteries in the liferaft grab bag. On top of that there is a smartphone per person on board, and quite often an iPad or two as well, all with GPS and GLONASS. About half the phones and tablets have full nautical charting apps as well as just GPS. It's hard to conceive of a situation in which all of these are simultaneously rendered unusable yet navigating the boat still matters.


Pete

My goodness.. where are you boating ?

 

[petem]

My goodness.. where are you boating ?

Solent I imagine ?

 

[prv]

My goodness.. where are you boating ?

I don't have dozens of GPSes as some kind of obsessive backup strategy; it's just that what used to be an expensive and mysterious item to be carefully mounted at the chart table and then worshiped is now a 50p chip incorporated into almost any non-trivial electronic device. Count up how many GPS receivers you have on board; it's probably more than you think.

The phones and tablets are there because it's 2016 and everyone has a phone, and when we're away for more than a night I also like to have a tablet to browse the Web of an evening on something with a little more space.

The four installed ones - well, the Seatalk receiver is the main one that feeds all the instruments and the main plotter. I also have a small plotter at the helm; being intended for standalone use on an open angling boat it has its own GPS rather than accepting any input, in fact the only connection it has is to 12v. The VHF needs an NMEA feed, and a £25 GPS puck is cheaper than an interface box to use the Seatalk. It also keeps things simple in that you don't need to make sure the instruments are on in order to use the radio. The old Garmin GPS128 I admit is a bit of a personal eccentricity, but I've been using them for 20 years and it works well with the Yeoman device for paper charts which I like to use when offshore (again for convenience and usability rather than paranoia about electronics failures).

The GPS in the grab bag is only sensible if you also have a handheld VHF, otherwise how do you tell people where you are? I don't expect to ever use it, but £15 on eBay for an old Magellan so why not.

The spare GPS in a tin under the forward bunk (another cheap old handheld from eBay) is probably unnecessary given the one in the grab bag, but it came first.

Solent I imagine ?

Just the Channel, say a triangle between Littlehampton, St Malo, and Falmouth. So not exactly world-girdling voyages, but I'd still like to know where I am. And with GPSes so cheap and ubiquitous, why not?

Pete