ECDIS Safety Settings

ECDIS has been the talk of the town. On every inspection on board, compliance with ECDIS procedures has been top agenda for the inspectors.

It will not be a new thing to say that good passage planning is the key for safer navigation. ECDIS now being a part of passage planning contributes to the safe navigation.

I had covered ECDIS in lengths earlier on the topic like

In these two posts I covered about the process of correcting the ENCs. Can we say we are all set if ENCs are corrected for Weekly corrections, T&P corrections, Navigational warnings and navtex warnings ?

But what if the settings on the ECDIS are not what it should be. Wrong settings pose even bigger threat to the safe naviagtion than the uncorrected ENCs.

In this post I will discuss about the what and how of all the settings on ECDIS.

Safety Settings

It is all in the name. Safety settings sets the safety parameters according to the ship’s static as well as dynamic particulars. That is a change ECDIS brought from the traditional paper charts. For example see this chart and I will ask one question.

Shallow area on paper chart

Can we say that blue part on this chart is shallow water ?

It is and it is not. For a small vessel with less draft, it is not a shallow water. For a big container ship with deep draft, may be.

So you see, the colors on the paper chart may not represent the shallow waters for all the ships. But on the ECDIS these can be set by the user according to their draft and other parameters.

There are 4 safety settings

  • Safety contour Setting
  • Shallow contour settings
  • Deep contour setting
  • Safety Depth setting

To enter a value for these settings on JRC ECDIS, go to

chart -> settings  and then choose “S-57/C-Map/ARCS.

Chart Setting on ECDIS

 

Now Let us discuss about these settings in detail and what values we need to enter in these settings

Shallow Contour setting

A contour is a line separating a minimum depth area. For example a 10 meter contour will be a line that separates waters below and above 10 meters depths.

The contours are in the value of 5, 10, 15, 20, 30 and so on.

Shallow contour value need to be used to tell ECDIS what is the value of shallow waters for our draft. This is the value of depth below which it is definite for the vessel to get aground.

The shallow contour value need to be equal to or more than the draft of the vessel.

Let us say the vessel’s draft is 9 meters and we enter the shallow contour value of 9 meter. The ECDIS will display 10 meter contour line as the shallow contour. If 10 meter contour is not available, it will take next contour as the shallow contour for the vessel.

The shallow contour lets the navigator know that between 0 meter depth and the shallow contour, the area is not navigable at all.

Shallow water contour on ECDIS

Safety Contour setting

Safety contour is the contour line above which we can navigate without any water depth concern.

So what is the depth of water required for the vessel to navigate without any concerns ? Off course it is the depth that complies with the company’s UKC policy.

Now again let us see it with an example. Vessel’s draft is 9 meters and at maximum speed, the expected squat is 1.1 meters. The company require the vessel to have UKC of 10% of the draft.

I assume you know the UKC calculation method and can easily arrive to the conclusion that this vessel would need 11 meters of water depth to navigate.

I have taken here the simplest of the case. In reality you need to follow your company’s UKC calculation sheet to arrive at the depths required to comply with UKC policy. This may take various factor such as sea conditions, increase in draft due to rolling, sea water density and the tide.

But the idea is to know the minimum depth of water at which you will comply with the company’s UKC policy.

This water depth becomes the safety contour setting. So if we enter 11 meters as safety contour setting, it will show 15 meter contour as the safety contour.

Some companies may give simpler instructions for the safety setting in the navigational manual. One form of these instruction can be based upon the draft of the vessel.

Safety contour settings on ECDIS

When safety contour value is entered in the ECDIS, it gives a safety contour line depths above which would meet the UKC requirement.

Safety Depth setting

So far we have only been talking about contours. We have not said anything about the actual safe depth. Safety depth is the only depth setting on ECDIS.

Safety depth is the depth of the water we can safely navigate upon. And it might sound repetitive but it is the depth that satisfies the UKC policy of the company.

In ECDIS we need to enter this minimum depth. It is same what we calculated as a simple example in safety contour setting. And as I said in that section, we need to follow the UKC calculation form of the company which may account for number of factors to calculate the safety depth required.

But the question is why do we need safety depth settings when we can navigate in waters above the safety contours ? This is because of two straight forward reasons

i) The depth above safety contour may not always be navigable.

This is in case of a shallow depth at one point in the navigable waters. Although we might be navigating in area above safety contour, this isolated depth pose a danger. Safety depth highlights this danger.

ii) The depths below safety contour may not always be non-navigable.

We can understand this If you allow me to again go through the safety contour value we entered. We entered the value of 11 meters and when we enter this value the ECDIS will take next available contour. This will be 15 meter contour.

Now the depths between 11 and 15 meters are navigable for us but it will show below the safety contour. So in the area between shallow contour and safety contour, safety depth will show the depth on which we can navigate.

Let us say we set the safety depth to 16 meters. On the ECDIS, all depths below 16 metes will be shown more prominently (in Black compared to others in grey color).

Safety depth on ECDIS 1

Deep water contour

This is a relative term and user is free to set as per what he believes could be deep water for him. For me deep water could be 50 meters while for others it could be 30 meters or 100 meters.

But there can be number of ways we can use the deep water contour setting.

For example you can set the deep water contour to show the maximum anchoring depths where vessel can drop anchor. So if your vessel can anchor maximum 105 meters depth, you can set the deep water contour to 100 meters.

Or if you are about to do ballast water exchange, you can set the deep water contour to 200 meters. This way you can easily see just by the color on the ECDIS if you are in depths where ballast exchange can be done.

The deep water contour setting can be used in number ways and navigators can use this to the way they wish to use it.

Differentiating the safety settings on ECDIS

Now let us see how the ECDIS screen will look like with all these settings. So let us say vessel’s draft is 9 meters and vessel require 14 meters depth to comply with company’s UKC policy.

So we have these settings

  • Shallow contour: 9 meters
  • Safety depth:  14 meters
  • Safety Contour: 15 meters
  • Deep Contour: 50 meters

And when I enter all these numbers in the ECDIS, this is how a ECDIS screen would display these settings.

different Safety settings on ECDIS

If you notice, for safety contour ECDIS has taken the 20 meter contour because 15 meter contour is not available.

There is another option in the ECDIS to use two colors to show these areas. When this option is selected, following will happen

  • Safety contour and deep contour will merge
  • Shallow contour and safety contour will merge

two color mode safety setting ECDIS

Or we can say that light blue and blue color will merge and become blue. Same way, grey and white color will merge and become white.

So there will be only two colors. One to show the shallow waters and other to show the navigable water.

Even in the two color display, it is not that we cannot navigate in the shallow waters. This is because it is showing the contour and not the depth.

In our example, the dividing line will be the 15 meters contour. The area below this contour will show as shallow waters (blue color). But as the safety depth is 11 meters (which will be below 15 meters contour), we can navigate in the shallow waters provided the depth is above 14 meters.

Danger detection settings

Entering the safety settings will warn us with an alarm when vessel enters in shallow waters. But when it gives the alarm it could be too late by then.

Danger detection settings can help in giving pre-warning of the dangers ahead. We only need to define the area in which we need the ECDIS to warn us.

We can define the area in two ways

  • Vector area
  • Sector Area

Vector area defines the area in length and width. Sector area defines the area in radius and width (angle).

Danger detection in ECDIS

Vector area defines the area in length and width. Sector area defines the area in radius and width (angle).

Let us define this area on JRC ECDIS. On JRC ECDIS go to Menu, Settings and then choose Alarm settings.

Alarm setting on JRC ECDIS This will open the Alarm settings pane.

Alarm settings on ECDIS

Under Vector and Sector section, you can define the area you want the ECDIS to look ahead. Once these areas are defined you can turn these on by going to “Ownship/Track” and then choosing “Settings”.

Danger detection area on JRC ECDIS

You can then choose to either “Vector area” or “Sector area”. You can even go to alarm settings page by clicking on “Set alarm limit” from danger detection section.

When you choose to display “Sector area”, it will look like this and ECDIS will trigger alarm if it detects any danger in this area.

Sector area danger on ECDIS

When you choose to display “Vector area”, it will look like this and ECDIS will trigger alarm if it detects any danger in this area.

Vector area detection ECDIS

Alarm Buzzer settings

I have talked about different safety settings on ECDIS. But these settings are of no use if do not have the alarm buzzer volume on. If the volume of the buzzer is off, ECDIS would not be able to alert the navigator.

But there are times when we need to keep the buzzer off. Like in high traffic density area when we are constantly monitoring the traffic. In this case frequent alarms will be of lesser value.

Navigators must use their professional competence to decide when they need to turn on the alarm buzzer.

On JRC ECDIS to turn on the volume of the alarm buzzer, go to “Main”, “Setting” and then choose “buzzer volume”.

Alarm buzzer ECDIS

This will open a pane from where you can increase or decrease the volume of different type of alerts.

Conclusion

I am a big advocate of use of ECDIS on board for navigation. In my opinion ECDIS is making the shipping safer. Sure there have been number of incidents because of user’s interpretation of ECDIS display but the increase in training and good practices has helped to cover many gaps.  Correct use of safety settings in ECDIS will definitely take it one step ahead .

Knowledge of what these safety settings mean can help in that.

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Capt Rajeev Jassal

About Capt Rajeev Jassal

Capt. Rajeev Jassal has sailed for over 19 years mainly on crude oil, product and chemical tankers. He holds MBA in shipping & Logistics degree from London. He has done extensive research on quantitatively measuring Safety culture onboard and safety climate ashore which he believes is the most important element for safer shipping.

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44 Comments

Krishnan
Krishnan
Aug 20, 2016

Sir please elobrate abt cat zoc zones

Rajeev Jassal
Rajeev Jassal
Aug 21, 2016

Categories of Zone of confidence (CATZOC) in a way tells us how accurate the data on the ENCs is. These are divided in different zones like A1 has the depth accuracy of 1% and C has accuracy of 5%. It all reminds us to take extra safety margins. I will try to cover in detail on future posts.

Raja
Raja
Feb 1, 2017

CATZOCs are increasingly important, in the absence of source data diagrams, to inform mariners about the reliability of the survey data that forms the charts. This is very important check during the passage plan. if you ignore ,may lead to grounding.

Muthukkumaran.V
Muthukkumaran.V
Aug 24, 2016

Sir,thanks for the post,very clearly explained abt the depth settings,Requesting more info on Ecdis.

Rajeev Jassal
Rajeev Jassal
Aug 25, 2016

Thank you Muthukkumaran. There are couple of posts on ECDIS. Check them out if these can be of some help.

Sagar
Sagar
Aug 26, 2016

sir can u tell, technical difference between rescue boat and lifeboat (if using lifeboat as rescue boat) except the hoisting requirement.

Rajeev Jassal
Rajeev Jassal
Oct 16, 2016

Rescue boat has recovery stropes to recover the lifeboat in heavy weather.

Capt. Chander Vart
Capt. Chander Vart
Aug 27, 2016

Excellent information. Explained in a very simple and easy to understand manner. Keep it up.

Rajeev Jassal
Rajeev Jassal
Aug 27, 2016

Thanks bro.. Glad to have you as regular reader..

Abbas
Abbas
Sep 13, 2016

Good day sir.Thank you very much for passing important informations .I found it very helpful.i wish u to keep writing blogs.It touched my heart the way u are helping others with your vast knowledge.Thank u once again sir.

Rajeev Jassal
Rajeev Jassal
Sep 14, 2016

Thanks for your kind words Abbas..

Aswini Kumar Barnwal
Aswini Kumar Barnwal
Nov 1, 2016

Good Day Sir.. It would be very great if you could explain about the isolated danger symbol in shallow waters as they are also a very handy tool for anti grounding alarm in Ecdis.

Rajeev Jassal
Rajeev Jassal
Nov 27, 2016

I will try to cover in one of the future blog Aswini..

Capt. Ram
Capt. Ram
Dec 15, 2016

Isolated dangers are automatically shown above safety contour i.e. in safe waters. However, they can also be seen below safety contours provided you select feature ''Isolated dangers in shallow water'' in few ECDIS

HF Zou
HF Zou
Nov 27, 2016

Sir, I think it is the funciton of safety contour , instead of your mentioned safety depty. and further more compared with chart example , the safety depth setting should be 14 meters in your example of "Differentiating the safety settings on ECDIS " - This is in case of a shallow depth at one point in the navigable waters. Although we might be navigating in area above safety contour, this isolated depth pose a danger. "Safety depth highlights this danger." tks.

Rajeev Jassal
Rajeev Jassal
Nov 27, 2016

I think that is exactly what I said in this article.. But if you read under "Safety depth setting" I have explained why safety depth is taken as 11 meters in this case.

Psingh
Psingh
Dec 9, 2016

Good day. Found this quite informative. Just a doubt. In general we keep the safety depth n contour values same. But in any other case safety depth can be greater than the contour values?

Capt. Ram Bahadur
Capt. Ram Bahadur
Dec 15, 2016

Yes, it can be the case where safety depth can be more than safety contour. However, u have to mark the no go area manually similar to paper charts because there will be unsafe waters when following the above water which will be not subjected to further alarms.

Capt.Igor
Capt.Igor
Dec 21, 2016

Great job. Thanks. Can the post be done in downloadable way?

Rajeev Jassal
Rajeev Jassal
Feb 5, 2017

I will try to include that fucntionality in near future..

Rehan
Rehan
Jan 4, 2017

Very well explained. What about the ports where the tidal range is high as 4-5 m? For example An aframax vessel of 12.5 m and Depth of channel is 13.6 m. Tide at the time of transit = 4.5 m so what would be ideal setting on ECDIS???

Rajeev Jassal
Rajeev Jassal
Feb 5, 2017

In this case you need to do the calculation basis what charted depth is safe for you. For example if with 12.5 m draft and with all the requirements (Company minimum UKC and squat etc) you require water depth of 14.5 meters. You need to remove the height of tide from it. That means the safety depth to be entered in ECDIS becomes 10 meters. Same method of calculation goes with other settings.

Sarthak Vohra
Sarthak Vohra
Mar 11, 2017

Sir, I have query regarding shallow contour settings in tidal ports havin 4-5 mtrs of tide for a particular window let say about 10 NM which requires minimum 4 mtrs of tide and the channel is about 50 NM. In this case what should be the settings of Safety depth / contour and shallow contour. Do i need to change ECDIS PARAMETERS again and again for different tidal range or same?? Let say my draft is 10.25 mtr EK and after applying squat and minimum UKC requirement from company my safety depth settings for pilotage waters becomes 13.37 mtrs (Speed 10 knts - squat - 2.62) and minimum UKC 0.5 mtrs. Here what tide to take to calculate my settings because its a 5 hours passage and tide is changing frequently and as i mentioned above for last 10 NM i need minimum 4 mtrs of tide. Can you please clarify? ECDIS parameters settings for sfety depth / contour and shallow contour. Will be highly obliged.

Rehan
Rehan
Jan 4, 2017

Sir, I would really appreciate your assistance if you please reply to my query asked in the above comment on my email id!

Rajeev Jassal
Rajeev Jassal
Feb 5, 2017

Let me know if you have any other doubt..

Mukesh Mamtora
Mukesh Mamtora
Feb 25, 2017

Thank you so much for your blog on safety settings in ecdis.it was really very useful.i had one doubt , is it ok to enter higher values in safety settings or else we should put the exact value which we get from calculation. can inspectors ask us ,that why you have entered little higher values? Thanks

Rajeev Jassal
Rajeev Jassal
Feb 25, 2017

Yes you can put higher values as long as you do not sail on danger depths for these higher values. For example if your safety depth is 10 meters and you put a higher safety depth value of 20 meters. Now if have sailed over 15 meter depth (unsafe as per safety settings but safe in real) then it will be considered as a matter of concern because you will no longer be able to distinguish between safe and unsafe depths. But if you are following those higher value of settings, like in this case you actually want to be in depths over 20 meters, you can do that and no one should question these higher safety setting values.

Mukesh Mamtora
Mukesh Mamtora
Feb 25, 2017

Tysm sir for your reply..

Sarthak Vohra
Sarthak Vohra
Mar 11, 2017

Sarthak Vohra 2 mins ago Sir, I have query regarding shallow contour settings in tidal ports havin 4-5 mtrs of tide for a particular window let say about 10 NM which requires minimum 4 mtrs of tide and the channel is about 50 NM. In this case what should be the settings of Safety depth / contour and shallow contour. Do i need to change ECDIS PARAMETERS again and again for different tidal range or same?? Let say my draft is 10.25 mtr EK and after applying squat and minimum UKC requirement from company my safety depth settings for pilotage waters becomes 13.37 mtrs (Speed 10 knts - squat - 2.62) and minimum UKC 0.5 mtrs. Here what tide to take to calculate my settings because its a 5 hours passage and tide is changing frequently and as i mentioned above for last 10 NM i need minimum 4 mtrs of tide. Can you please clarify? ECDIS parameters settings for sfety depth / contour and shallow contour. Will be highly obliged.

Rajeev Jassal
Rajeev Jassal
Apr 30, 2017

In this case you either you need to change the settings again and again or you can just calculate and ensure that you have sufficient UKC and keep the same settings. This is a particular situation but the idea is that we need to be sure of our UKC and in this case we need to be very attentive as the information could be misleading.

Nish Walker
Nish Walker
Mar 15, 2017

Hi sir, it's a great article. i've referred to many ECDIS Articles before Venturing into yours, couldn't help noticing most of those article said Deep Contour is to indicate the waters upon which a vessel experience squat, well it doesn't make any sense because Deep contour is twice the ship's deepest draft and safety contour(indicates safe waters) is ship's draft+Squat+UKC+CATZOC, which is obviously lower value than deep contour. So when a vessel sailing in safety contour would not squat let alone aground* but she will experience squat in Deep contour??. To put that in perspective a vessel could exp squat in deep contours , when she sails towards safety contours only to experience more or much worse!! . Maybe I've gotten it all wrong !! Pls correct me if i'm wrong.

Rajeev Jassal
Rajeev Jassal
Apr 30, 2017

You are right Nish..

Jun
Jun
Mar 27, 2017

Gud day Captain! can you kindly give me your opinion about these formula which I got from an NK surveyor in Brisbane. Safety contour = (Draft + UKC) - Height of tide and, Safety Depth = (Draft + Squat + safety (as per company)) - Height of tide. thanks for replying, God bless.

Rajeev Jassal
Rajeev Jassal
Apr 30, 2017

It is right about Safety Depth but safety contour will be same as safety depth as it automatically takes the next available contour.

M LAKSHMI NARAYANA
M LAKSHMI NARAYANA
Apr 29, 2017

SIR SIMPLY SUPER,VERY HELPFUL,U HAVE VAST KNOWLEDGE ON DIFFERENT TOPICS,THANK U VERY MUCH

Rajeev Jassal
Rajeev Jassal
Apr 30, 2017

Thank you for being a reader ..

Buenfil Bas
Buenfil Bas
May 25, 2017

Thanks for this post,.

Rajeev Jassal
Rajeev Jassal
Aug 28, 2017

Thank you for reading Buenfil...

Sandeep Vithal Band
Sandeep Vithal Band
Jun 9, 2017

Oh I just finish Ecdis course over here without spending Single Penny. Many thanks Capt. Rajeev Jassal . You are doing great job.

Rajeev Jassal
Rajeev Jassal
Aug 28, 2017

Glad to hear that Sandeep...

Viswanathan Venkatesan
Viswanathan Venkatesan
Jun 23, 2017

Nice Explanation sir. Can you explain about Limiting Danger Line (LDL) in detail sir.

Freddy Nitash
Freddy Nitash
Aug 2, 2017

Sir can you help about confirmation display of ECDIS Chart1 (PL4.0) for ECDIS JRC JAN-901B, procedure how to demonstrate.

Amit Rathi
Amit Rathi
Aug 9, 2017

How to check CATZOC on JRC ECDIS 901B, plz comment ...!!

Moi ty
Moi ty
Aug 27, 2017

Thanks sir for sharing ideas

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