Should the Watch Officer Maintain a Plot on Paper With ECDIS


#1

On a ship that uses on ECDIS and paper charts as a backup is it more prudent to maintain a DR and plot fixes on the paper charts just the same as if there is no ECDIS or is better for the watch officer to use ECDIS the same way that it would be used if the backup was another ECIDS?

This is what Bowditch says in Chapter 7

Until ECDIS is proven to provide the level of safety and accuracy required, the use of a traditional DR plot on paper charts is a prudent backup, especially in restricted waters. The following procedures apply to DR plotting on the traditional paper chart.

But in Chapter 8 it says this:

If the ship is equipped with an ECDIS, it is reasonable for the navigator to simply monitor the progress of the ship along the chosen track, visually ensuring that the ship is proceeding as desired, checking the compass, sounder and other indicators only occasionally.

I know that Transas ECDIS allows bearing and ranges obtained by visual methods or radar to be plotted on the ECDIS. Seems to me that is the way to go, along with such methods as parallel index lines on the radar as well as visual monitoring rather than either the Bowditch chapter 7 or 8 method


#2

I wouldn’t trust​ Bowditch with this topic as the last revision was published 16 years ago.

In congested waters, there isn’t really time for an OICNW to Conn the vessel and be placing constant, frequent plots. Plus, it’s fairly easy to compare radar to ECDIS to see that they agree. What intervals are you thinking?


#3

I agree with what the IMO says:

1.6 ECDIS should reduce the navigational workload compared to using the paper chart. It
should enable the mariner to execute in a convenient and timely manner all route planning,
route monitoring and positioning currently performed on paper charts. It should be capable
of continuously plotting the ship’s position.

This is what the IMO says about back-up:

  1. BACK-UP ARRANGEMENTS

14.1 Adequate back-up arrangements should be provided to ensure safe navigation in case of an ECDIS failure.
.1 Facilities enabling a safe take-over of the ECDIS functions should be provided to avoid that an ECDIS failure develops into a critical situation.
.2 A back-up arrangement should be provided facilitating means for safe navigation of the remaining part of the voyage in case of an ECDIS failure.

Being able to ensure safe navigation in case of an ECDIS failure may in some circumstance require that a up to date paper chart with track-lines be available on the chart table, in reduced visibility in restricted waters a full nav plot might be required to switch seamlessly. But in that case the watch officer would require additional assistance.

However I’ve been told that using the ECDIS that way makes some mariners “feel uncomfortable”.

Here’s the guy that wrote the book at the Nautical Institute for example

There is never a situation where you are allowed to have just one source of chart data. In general, you either have to have two ECDIS (one the primary, the other the backup), or a single ECDIS with the backup being the use of up-to-date paper charts. In this latter case you need always to have the correct paper chart on the chart table, with its route plotted and also for regular positional updates to be plotted.

This however violates IMO 1.6

1.6 ECDIS should reduce the navigational workload compared to using the paper chart. It
should enable the mariner to execute in a convenient and timely manner all route planning,
route monitoring and positioning currently performed on paper charts.

I can’t see how ECDIS can reduce workload if the traditional full nav plot has to be maintained simultaneously to monitoring the ECDIS.


#4

It can’t. I started to reply something similar to your quoted source about having plots on paper in case you lost the ECDIS then thought better of it. You should have the chart out and ready with track lines for the voyage though.


#5

It always comes down to the 3rd rail of maritime politics: manning.

If immediate substitution for a failed ECDIS is necessary, you can’t just press the pause button while the previous positions are plotted. Either you have a continuos paper plot going as a back-up, that can be referred to at any time, or you don’t. To do them on paper in a proper manner requires trained personnel who are not in a fatigue-induced fog. The manning standards should honestly reflect this. Or you have the additional ECDIS as the back-up. That also has a cost, but that’s too bad: you can’t have it both ways.

Regardless of whether you use ECDIS / ECDIS or ECDIS / Paper, the personnel tasked with reading, interpreting and acting upon said positioning information should likewise not be in a state of fatigue-induced fog that would render them incapable of using it properly.

I suppose, however, that should calamity strike (simultaneous failure of both ECDIS units, or maybe an ECDIS failure plus a broken pencil) you could just hit the “hyperspace” button and hope that you don’t burn up on reentry.


#6

I’ve done a lot of navigating, but I’ve also observed how mates navigate.

In general I think that keeping a plot on a paper chart during times of high workload reduces rather than increases situational awareness. So it boils down to being able to switch to the backup if the ECDIS fails. So this is the standard:

Facilities enabling a safe take-over of the ECDIS functions should be provided to avoid that an ECDIS failure develops into a critical situation.

Aside from the eyeball either visual or radar the first line of defense if the ECDIS fails is a quick distance off radar range can be done in few seconds. Next the GPS continuously shows the bearing and range to the next waypoint as well as the cross-track error. To start a paper plot a radar bearing and range can be plotted in about 30 seconds. The slowest method would be plotting a GPS lat and long which is the the go-to method for mates even though it’s slower. From there laying out DRs doesn’t take much more than a minute.

A point worth making is that when the ECDIS goes down it’s failure is obvious (in my experience anyway, the screen goes black). However when the paper plot fails, not a broken pencil but a plotting error, which are very common, they often go undetected. The weak link is the process in transferring the lat/long info from the GPS to the chart.


#7

We had a situation on a non ECDIS vessel where our primary GPS went out in the Singapore straights. That was the GPS that fed data into the radars for our radar display track lines, which is how we navigated those waters without plotting constantly on paper. That required us to then have a helmsman, a mate plotting every 3-4 minutes, and a mate at the Conn. That’s very hard to pull off with modern manning levels.


#8

In college world, should they? probably.

In the real world, should they? Should they fuck

If you have ECDIS with radar overlays you can see immediately if land matches with the displayed GPS position.


#9

In my opinion, ecdis is another tool to provide more awareness and redundancy. This adds to the workload for the sake of that.


#10

Switching from paper charts to ECDIS is in some ways like the switch from sail to steam. For a time ships kept a foot in each world. People were understandably reluctant to make the switch, what if the engine failed? So for a time ships had both sails and power.

But how much sense did it make to maintain both systems aboard ship? After the full switch was made it enabled the industry to build up the entire infrastructure of marine engineering we have today, the expertise at the schools, the unions, at the regulators and so forth.

With regards to the back-up this is what IMO says:

  1. BACK-UP ARRANGEMENTS
    14.1 Adequate back-up arrangements should be provided to ensure safe navigation in case of an ECDIS failure.
    .1 Facilities enabling a safe take-over of the ECDIS functions should be provided to avoid that an ECDIS failure develops into a critical situation.

.2 A back-up arrangement should be provided facilitating means for safe navigation of the remaining part of the voyage in case of an ECDIS failure

The term back-up arrangement would include not just having the physical charts on board but also a written procedure on board as to how to make the switch over.

There are two issues here, having a procedure in place in the case of ECDIS failure and having a procedure that will withstand PSC scrutiny which will inevitably come at some point.


#11

What if Sun Spot Activity or whatever (Trump policy??) should shut down GPS altogether?
Nearly all navigation systems in common use are dependent on GPS being available and most Navigators are as well.


#12

ECDIS should be required to have a software feature whereby sextant readings are input, the ECDIS software does the calculation, and line of position are displayed.

ECDIS integrate with anemometers and speed logs should be able to calculate pretty well what the effects of wind and current are on the movement a vessel, so should be able to give a some what accurate DR position.

Even if there was no GPS, it doesn’t mean you need any paper charts.


#13

ECDIS should also be connected to an inertia navigation system.


#14

Even if it doesn’t do it in that fancy of a way (which would be really nice) you can input positions manually. There’s no need for paper charts just because the GPS goes down.


#15

Dependence of GPS is not the point of this thread, that’s been covered in other threads, what about the ships using ECDIS back-up? How is using paper chart back-up or not change that?

WIth regards to ECDIS most ships likely keep some small scale charts on board for convenience. If plotting sheets are needed mercator sheets can be easily made on board or the “sailings” can be used.

As has been mentioned, with Transas bearing and ranges can be entered manually, I don’t see why you couldn’t enter celestial LOPs.


#16

All of us used to plot our position on paper charts all the time. So why not make a plot every couple of hours?


#17

What are you going to do when you finally go paperless? That’s the question. Most ships I encounter any more are paperless.


#18

Why? Position information comes from radar, visual and GPS. With ECDIS, radar information is used in two ways, parallel indexing or similar and secondly bearing and ranges. With two ECIDS radar or GPS information is not “processed” or plotted on a paper chart in anyway. Why is there a need to process the information on paper charts with one ECDIS? It takes time and attention yet adds nothing to situational awareness.


#19

Why? Position information comes from radar, visual and GPS. With ECDIS, radar information is used in two ways, parallel indexing or similar and secondly bearing and ranges. With two ECIDS radar or GPS information is not “processed” or plotted on a paper chart in anyway. Why is there a need to process the information on paper charts with one ECDIS? What does it add? It takes time and attention yet adds nothing to situational awareness.

If the redundancy of the paper chart is required why not require it when the back-up is ECDIS?


#20

You answered your own question: beacuse backup is a 2nd Ecdis.