Ecdis


#1

Interested to know if y’all have any expert comments regarding potential problems with an ECDIS- technical and otherwise (meant overall efficiency and alertness on the Bridge Team)


#2

As an ECDIS/ECS e-Nav instructor, here’s a few of my favorites:<br><br><span style="text-decoration: underline;]<strong>Number one pitfall: Using ECDIS as a primary collision avoidance and navigational tool. Keep your eyes out the windows!!!</strong></span><br><br>In case you skipped the sentence above:<br><br><span style="text-decoration: underline;]<strong>Number one pitfall: Using ECDIS as a primary collision avoidance and navigational tool. Keep your eyes out the windows!!!</strong></span><br><br>In fact, using ANY e-Nav system as your primary position fixing or collision avoidance tool. <span style="text-decoration: underline;]<strong>Keep your eyes out the windows!!!</strong></span><br><br>Number two pitfall: Assuming that the ECDIS/ECS is correct when your eyes and/or radar tell you something else. Verify, verify, verify. I had a mate tell me that a very real target wasn’t there because he “isn’t on AIS, Cap!” <span style="text-decoration: underline;]<strong>Keep your eyes out the windows!!!</strong></span><br><br>Verify, verify, verify, and be skeptical until you’re satisfied that your vessel’s electronics are good. Do not extend the same to anyone else. Never assume that a target’s systems are correct.<br><br>Cross-check ECDIS information with what you see visually and on radar.<br><br>Technical issues:<br>1. GIGO. G-arbage I-n G-arbage O-ut. Faulty information from or about your ship’s sensors leads to faulty ECDIS display info. This can be caused by improper setup, Operator error, etc. For example, improper setup info regarding vessel dimensions, or faulty antenna placement info coming in from AIS/DGPS etc. <br>2. Improper datum for the geographical area you’re in. This usually happens when a foreign ship enters U.S. waters with a datum other than WGS-84 entered in the ship’s GPS/DGPS.<br>3. Accidental or intentional offset of the ship’s position entered into the ECDIS. On the Transas ECDIS/ECS systems this can be done quickly and easily by ANYONE, even the cook for god’s sake! It is not password protected and it can kick your ass. One way to verify a proper screen presentation is (if your system allows) to overlay a radar image on the ECDIS screen. If the radar lines up with the chart, you’ve got a pretty good indication that all is well with your position information. If it doesn’t, anyone who votes for ECDIS over radar should be spanked.<br><br>I’ll probably think of more after I post this, but this should get you started.<br><br>Doug<br>


#3

Thanks doug for the detailed info.<br><br>A fellow mariner once told me that he saw the ship’s position jump (instead of smooth movement) at about 15 sec intervals on large scale or ‘zoom in’ setting…which is an important fact when manoeuvering in very restricted waters…<br><br>Agree with you that radar overlays are the way ECDIS should be set… and best placed for improving navigational safety<br><br>Talking about AIS - i have to add that I have found CPA calculation by the ARPA differing (and less accurate) when calculated from AIS info in comparison to the old fashioned manual/ auto acquisition of the target echo…I always recommend my colleagues to disregard the AIS-CPA readings and refer to the latter. <br><br>By the way- have you seen any long term effects on the use of ECDIS on the watchkeepers and Masters (e.g. over-reliance / dumbing down / over-confidence / video-game mindset etc)<br><br>In a nutshell - Do you consider parallel-indexing the best and most effective check for an ECDIS user. <br>(i am not considering visual bearings - it is soon becoming an extinct tool and going the sexant’s way !)<br>So far we have seen 2 'ECDIS assisted casualties- Royal Majesty and COSCO Busan…do you know anymore such case studies…?<br><br>IM


#4

The lag is most likely a function of the target’s AIS reporting interval. At large scales this is common and is a bit weird when you’re used to seeing smooth displays on radars. The way I prioritize ECDIS use doesn’t make this an issue for me. In restricted waters I’d be “out the windows” myself, or in bad visibility I’d be on the radar with a mate perhaps on the ECDIS. <br><br>Regarding the differences in ARPA and AIS plotting: If you’re referring to an ARPA radar that is capable of displaying AIS target info, the radar is using the same math as an ECDIS to show CPA/TCPA for its AIS targets. You may have noticed on such radars the same lag as mentioned above, when the radar blip will out-run the AIS designator from time to time. Again, a function of AIS reporting interval or more rarely an issue with VHF radio reception. When maneuvering while using ARPA and AIS, I’d personally place more trust the AIS CPA data given the fact that it allows for maneuvering. ARPA goes to hell as soon as you or the plotted target turns or changes speed. It doesn’t settle down again until both of you are in a steady state and only then can ARPA generate another useful plot, after three minutes. <br><br>Any eNav system has the potential to induce over-reliance / dumbing down / over-confidence / video-game mindset etc. The biggest challenge is fighting the complacency that can develop in a wheelhouse full of bells and whistles. The next challenge is training the younger generation of mates to look up from time to time. There is at present no replacement for a set of eyes and ears attached to the brain carried in the skull of a person who has sailed for years. I should probably qualify that statement by pointing out that this needs to be a functioning brain, as we’ve all, I’m sure, sailed with guys with decades of experience who seemed to lack just that…<br><br>I am a huge fan of parallel indexing. I am amazed by the majority who don’t use, either by choice or lack of training, this fabulous tool. PIs just make life so much easier, in addition to being a good way to check your ECDIS. In the real world, how much easier can it get? “Do you see this line, Mr. Mate? This is your intended course over the ground. Steer the ship to keep it pasted on that rock, and nothing to the other side of said rock. I’m heading to my rack. Call me if you need me.” <br><br>Another reason to use PIs: They can enhance your career ambitions. In my present line of work we use full mission bridge simulation for student and candidate assessment, at all levels from entry level pre-hire to Pilot applicants. I can assure all who read this that if you one day find yourself in an assessment environment, you will add to your score (and earn some respect from your assessors) by making the use of parallel indexing part of your radar routine.<br><br>I’ll be back in my office on Monday. I will see if I can dig up some case studies. <br><br>Did you hear about the AIS assisted collision? Two watch officers on different ships making passing arrangements using the text messaging feature of AIS ran their ships into each other. True story. <br><br>The fun never stops.<br><br>D<br><br>


#5

Interesting reading at the Nautical Institute’s AIS forum:<br><br><a title=“Nautical Institue AIS forum “reported problems” page.” target="_blank" href="http://www.nautinst.org/ais/reportedProbs.htm]http://www.nautinst.org/ais/reportedProbs.htm


#6

I love ECDIS and think it should be used on every ship but I use it sparingly under 2 conditions:<br><br>1) I glance at it with frequency to check for “ahh fuck” situations (it really saved me once when I made a mistake and turned early)<br>2) Situational awareness (The last use of this was on the Houston ship channel… I had lost track of the bouy number I was passing and the pilot was busy so I got the number off the ecdis and proceeded with normal terrestrial nav)<br><br>I might also use it during rapidly changing circumstances where a deviation from the voyage plan is immediately unnecessary… but I have yet to come across this problem.<br><br>AIS I use extensively but ours is tied to the arpa so the only time I use AIS data on the ecdis is to check whether a target is in a particular traffic separation lane.<br><br>Otherwise I leave the thing alone.<br><br>To answer your parallel indexing question… I’m a HUGE fan and use it for everything from assuring I’m staying on track to making difficult turns.