When the GPS Goes Belly Up

We have at our company a new simulator training exercise, not mandated by any agency. I wonder how many companies out there have a similar course?

We use Seattle Maritime Academy’s full mission bridge simulator to simulate a situation where a ship has lost all GPS and ECDIS, and has to navigate in a crowded, complex waterway for long periods, using only radar and charts, at night.

The training was designed and supervised by a senior captain who still sails actively. The purpose is to make sure mates nowadays, some with many years of experience in charge of a watch, can safely navigate in a way which was commonplace up to the 1980s, in case an emergency forces them to do so.

For the first part of the two-day exercise, a team of two mates navigates a 300’ LOA container ship through the San Juan Islands of Washington, through a network of intersecting channels, with high tidal current. The navigators have to keep the vessel on track, while avoiding traffic.

The second day is harder. The navigators pilot through the length of San Francisco Bay at night, using only radar and navaid lights, until out to sea.

The critiques the trainees gave afterwards were honest: the training was valuable, but stressful to say the least. Everybody says they can navigate, as opposed to using an ECDIS–until they are forced to do so. Here some navigators did well, and some got through by the skin of their teeth. Now the company knows who needs additional training.

Any other companies doing non-mandated navigational training like this, as opposed to collision avoidance training?


Not that I’m aware of. Most if not all deep-sea companies that I worked for had requirements above and beyond mandated minimums, courses which are provided at the union school but I never took anything like that, closest was a shiphandling course which covered some piloting techniques.

Where I learned is first at the Navy Quartermaster A school where the basics are taught and then practical in Alaska. A CG/Navy bridge navigation team provides a close equivalent to an ECDIS with a continuous paper plot (min 3-minute fixes) except the resultant information is transmitted verbally rather than visually.

A related but different skill is learning to pilot by eye, here there are two separate but overlapping categories, one is becoming familiar with a particular area and the second is learning how to quickly orient one’s self in an unfamiliar area.

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I know of one company doing similar, but if you used the simulator at Seattle Maritime, that’s probably the one you work for.

A full ECDIS allows direct plotting of bearings and ranges so a plot can maintained without GPS.

A first step to shift away from total GPS dependency is to require a plot at intervals when in pilotage waters, same as was done with a pilot on board. Also a requirement to use parallel index lines on the radar when available.


On one of the cutters I was stationed on we had a gyro stabilized camera and I could shoot bearings and use radar ranges.

It took a little getting used to but I could do one minute fixes when I got proficient.

I am assuming he is considering a loss of the ECDIS (or chart plotter as I believe their vessels use, but most modern chart plotter software has the functionality as well, just somewhat less intuitive) as well as the GPS.

How often are the GPS systems on your vessels going ‘belly up’?

I’m not saying that knowing how to do it that way is not useful. I made my first transit of the Inside Passage using a dog-eared copy of Cap Hansens logbook we had to keep inside a ziplock bag in the wheelhouse, used a stopwatch and rough mag compass bearings the whole way. Knowing how to navigate that way enhances your use of ECDIS/Chart plotting software.

Some time ago I purchased a personal copy of Coastal Explorer and a GPS dongle for my laptop. It takes approximately 30 seconds for me to get that out of the bag, fire it up, attach a cable to the wheelhouse monitor (or shove it out of the way) and I’m back using the best navigational tool ever invented. All my routes and notes are right there. I know how to take bearings, ranges, etc. I also know doing those things takes away my situational awareness from other things that may need my full attention.

Let me ask you something. Do your mates know where the power supply is for the radar/sat compass/GPS? Not ‘It’s that breaker’ but the actual power supply. Do they know where an alternative power supply is? Could they, in an emergency, rig a power supply to regain functionality to their wheelhouse equipment, say following a fire? Some of your older captains certainly do. Do the new mates?

The scenario described sounds less likely than a loss of radar as well. In fine visibility, ranges and bearings can be taken. It was done for many years. Bad weather makes that much more difficult even for the most skilled mariner. The prudent thing to do in that situation would be to pull back, repair the wheelhouse equipment, then continue on with full wheelhouse functionality. You might want to consider adding that to your training. I have seen too many situations where the wheelhouse crew fumbles around under the dash trying to fix things they’ve never looked at before. That’s why I got the emergency laptop.

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Yes but if there is loss of a full ECDIS there is an arrangement for a back-up, either a fully independent second ECDIS or paper charts.

That’s not necessarily the case with an ECN setup.

So in the case of loss of GPS the answer is shift to terrestrial plotting but if it’s failure of the ECDIS it would be to shift to the backup.

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Now, THAT’S what I am talkin’ about! What an excellent idea! Uh-oh! Sea story alert!

First OOD watch on my beloved 18500 DWT (?) Mobile was departing Hong Kong at night when every junk was littering the sea as far as to be seen. Captain in sea cabin so soundly out unable to awaken, time running out to alter course with his blessing. XO on the bridge was not being any help probably just to see what I would do. I mean he was a merchie and was wise beyond my comprehension. My Quartermasters were doing a fine job keeping me from shoal water so I could concentrate on not running over anyone. It became a drill of finding which of the “herd” was drifting left, who was drifting right and steaming a line in the middle that was more or less along our desired track and adjusting speed upwards as the herd thinned out. Once realizing each little white light was interested in keeping out of the way the whole thing became a lot easier. The XO was obviously quite pleased that I was able to keep all three of us out of jail.

This simulator scheme strike me with perfect sense for training, qualification and re-qualification of bridge watch standers. Remember the Kobayashi Maru scenario? Any of you pukes ever go through the “every 6 months you bet your job” with the airlines? That is a simulator drill where they try to load the flight deck team up with equipment failures until they can’t handle it. There is a pass-fail point. Should work for ships, too but slower.

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I wrote a bit about it in the INS thread IIRC, but the short version is that it’s happened to me personally with more than one boat. One had a recurring issue where all (4? 6?) GPS receivers would lose signal simultaneously, which I eventually traced to a faulty unit somehow sending out an interfering signal.

I’ve also lost Transas entirely, and learned the hard way that paper chart backup has a very real purpose. You have no idea how hard and fast a broken window will mess up your day, unless you’ve been there.

:smiley: That’s exactly the point of the training. Everyone thinks they can navigate without GPS/electronic charts–until they are forced to do so. Everything is failsafe–until it fails.

The worst case scenario is that you lose GPS and electronic charts in Discovery Passage or Seaforth Channel in heavy traffic. The safest mode of operation is for the navigator to keep navigating the way it used to be done, with perfect safety, until the backup laptop is sorted out. But there is no law that says the backup has to work either. And in the minutes they are fumbling around sorting out backups and powers supplies, the ship still has to be navigated.

I always think of Sully Sullenberger landing an Airbus 320 without power in he Hudson River. He didn’t do it because there were backup engines on the plane. He did it because, he said, “I’ve been making small, regular deposits in this bank of experience, education and training. And on [the day I had to land the plane in the river], the balance was sufficient so that I could make a very large withdrawal.”


The point is are you using data driven analysis to look at weak points in your operation and making proper preparation for potential emergencies or are you just nostalgic for the old days.

Anyone that is nostalgic for the old days either didn’t actually do much in stressful situations under the old way or doesn’t sail anymore.

It did not used to be done in perfect safety. Not even close. There are a lot of bones on the sea floor that prove it.

As pointed out previously, I would suggest the successful transit in this simulation would depend entirely on the navigator’s experience and familiarity with the route. Most pilots ( not all! ) aught to be able to accomplish this scenario given their extensive experience and knowledge of the traffic patterns, reporting points, tides/currents, nav aides, and their situational awareness while looking out the windows. While not a pilot myself, on my home turf I am reasonably confident that I could close the laptop and get where I’m going safely while managing the above mentioned factors with only radar, radios etc. Given the same scenario in an unfamiliar port the situation would be quite uncomfortable indeed. It’s an interesting and perhaps humbling training exercise to say the least.

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I think the key point is the radar. Most experienced mariners could navigate a coastal route using radar ranges.

Looking at possible scenarios where this happens, the radar is likely knocked out as well. That’s why I think training in restoring modern navigation equipment is just as important as knowing traditional nav techniques.

Even without the radar knocked out, poor weather when Murphy knocks could make the radar range less accurate/not always available. In heavy traffic with numerous small craft that don’t always follow the rules having to use the radar as both a navigational tool and collision avoidance tool means one thing will suffer.

I see this come up a lot, and I think the concern is the lack of ‘sea sense’ in younger mariners from too much focus on electronic nav equipment. The problem is the only way to gain that sea sense is long hard hours navigating that way in stressful situations. Giving some simulator experience is a good step.

I ran both a large OSV and a small container ship without any chart plotters. We navigated by eye with radar when inland.

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He works for Coastal Transportation.

Instead of trying to train each officer how to do it as an individual why not divvy the task of navigation up into separate simpler tasks? One officer with the conn and one keeping a plot and setting up parallel index lines for example

The point of diminishing returns is going to be hit a lot quicker trying to get each officer up to the point where each could do it themselves then it will be to train them to break the task down into parts and learn how to operate as a team.

Don’t know much about aviation but to me this seems like a difficult landing.

When he attempted to maneuver the jet, he found the controls had absolutely no response. The 120-ton vessel loaded with 296 people was hurtling more than 6 miles above the ground, and there was no way to control it.

Then things got worse.

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If you have radar overlays on ECDIS you don’t really need to plot bearings and ranges, you can see instantaneously if the radar image matches up with the coastline.

It’s pretty stupid having two pieces of electronic equipment like the radar and the ECDIS where you have to manually transfer data from one to the other when it is pretty straightforward to combine the two and have the radar information appear on the ECDIS screen.

When on a bridge simulator course the first thing to do is turn on radar overlays, you can see immediately when the course operators introduced a position offset in the GPS to try and confuse you.

As it is such a great navigational tool I still can’t understand why radar overlays aren’t a mandatory requirement on ship that have ECDIS and radars, the technical challenges for compatibility aren’t that great once they are made mandatory by legislation.

Some people don’t like radar overlays because they think it makes the ECDIS screen look cluttered, but that is only with ECDIS systems with a rubbish user interface, on ones with a good user interface it works pretty well.

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How are the radar and ECDIS going to match without a GPS signal?

Many ECDIS can be put into a automatic DR mode, some go into it automatically with no GPS input.

On some ECDIS makes you can drag and move the ships position manually so it matches up with the what the radar is showing then it uses inputs from speed logs etc. to calculate what your DR future position, if the radar and ECDIS start going out of sync again due to an error in the DR then you just click and drag the ships positions so the radar image and coastline match up again.

More or less the same as a range an bearing but instantaneous.

On simulator courses the course operators add GPS offsets of 100 meters+ randomly, so you can see when they do it immediately with radar overlay.