Common ecdis use errors

common ecdis use errors

Firstly, it is important to identify the risks that are associated with the ECDIS system and over-reliance on them, before full implementation. In this case, we need to use the manual update feature so that we can get the alarm on the ECDIS if the vessel crosses this line. The frequent failures of ECDIS include the fluctuation of the information data due to the lack of 3.1 Development projects of uses of ECDIS in Tanzania.

Common ecdis use errors - talented

Best practices to avoid 7 of the common marine navigation mistakes that can lead to accidents

A vessel was in transit through the Suez Canal with a pilot on board. The vessel was supposed to move along the centerline of the canal, however, as it deviated from the center line, the pilot and the crew on the bridge used the corrective wheel and thrusters to counteract this deviation. By that time, the ship had swung heavily and approached the bank on the opposite side. The stern of the vessel touched the rocky sea bottom. There was a heavy thud and a vibration in the wheelhouse and engine room. The ship's speed dropped and increased again. All ship crew noticed the vibration. The engine room called the bridge to confirm that everything was in order. Both watches confirmed to the pilot if everything was in order, to which the pilot replied in the affirmative. The vessel picked up speed again and resumed movement along the canal. The most senior officer of the watch did not call the captain and did not discuss the incident with him later. However, below the waterline, the bow of the hull was damaged and its strength in the impacted zone was significantly reduced. There was a slight deformation, but below the waterline. Later when the ship was loading the cargo at port, there was again a big dull sound, and the OOW noticed that water gushed into the ballast tanks No. 1, 2, 3 at the port side. Due to the constant stress on the damaged, deformed and worn plate, the weak zone collapsed and failed.

Often we have seen junior officers on board ships respond "Yes, sir" to any given task, and later find that something else has been done about the subject.

Various incidents on board require the seafarer to act and react according to predefined and predetermined patterns during routine and emergency situations. For a variety of non-standard tasks, companies have also introduced procedures for group meetings, on board training and risk assessments. These interactions help the captain or other team leaders recognize the merits and weaknesses of their team members before assigning a task. Communication between the team leader and team members, or between team members, is key here in avoiding the occurrence of human error chains by identifying and eliminating their root causes.

Strengthen the communication between crew members

Numerous groundings and near misses have occurred on ECDIS equipped ships that could have been avoided but for failures in the setup and use of ECDIS. Like most of the world’s merchant fleet trading internationally, your ship(s) is most likely equipped with an Electronic Chart System (ECS) or Electronic Chart Display and Information System (ECDIS). Maybe it is fully compliant with the IMO requirements for an ECDIS and therefore the primary means of navigation, or perhaps you are still transitioning towards an approved system.

The primary function of ECDIS is to enhance the safety of navigation, but experience is showing that installation and approval alone are not enough to achieve this goal. Comprehensive training, including type-specific familiarisation, and updated Safety Management System (SMS) procedures are essential to ensure safe ECDIS use without introducing new risk.

Furthermore, Port State Control Authorities have reported an increase in deficiencies concerning ECDIS use following Concentrated Inspection Campaigns (CIC) on safe navigation. The age of e-Navigation is firmly upon us and the transition to electronic-based navigation is a fundamental shift away from the not-so-distant past where azimuth sights, sextants, and parallel rulers were the indispensable tools of every navigator.

A base ENC with limited chart information compared to the unfiltered chart of the same channel and location. Overuse or improper use of filters and contours may result in ambiguous displays of soundings and potentially dangerous interpretations.

Risk Factors

Everything a ship’s officer can do on a paper chart must be feasible on an ECDIS device; i.e. a functional equivalent. This includes the most basic of navigation tasks such as manually plotting the ship’s position by range and bearing; thorough passage planning, including voyage notes and callouts; marking of nogo areas; applying manual chart corrections … and so on. The reality is, ECDIS can do all this and a whole lot more.

Modern ECDIS systems are now so functional that inadvertent actions or settings may be applied, which can then go unnoticed. Safety contour and safety depth functions, for instance, may be misused rendering the alarm meaningless. Display settings may reduce the visibility of essential information from the screen as previously shown.

Position data and/or reference points may have unwanted offsets – for instance, when was the last time the CCRP (Consistent Common Reference Point) settings were checked? Are they correct for multiple antennas and radar systems? Are the CCRP settings locked and password protected against accidental meddling?

Manual position plotting can be done quickly and easily on an ECDIS, but it is critical that officers familiarise and regularly practise this function.GPS positions should be cross-referenced using visual/ radar range and bearings.

Safety contour and safety depth settings can drastically affect the display and when alarms are given.

The Safety Contour Depth should normally be set to the “Vessel Safety Draft,” which is commonly calculated as:

Vessel Safety Draft = Vessel Draft + Dynamic Squat + Safety Margin.

The Safety Contour marks the boundary between “safe-water” and shallow water and can be set to give an alarm if the ship is approaching the contour.

Consistent Common Reference Point settings and locations of antennas, radars and other reference points should be set correctly and frequently checked.

These are just a few of the unwelcome risks that may be introduced unintentionally if navigators are not properly trained and instructed in the correct use of the systems fitted aboard their ships.

Common operational mistakes

When properly operated, ECDIS is an exceptional tool that drastically improves situational awareness and operational efficiency, and can reduce errors. On the other hand, over-reliance or lack of familiarity can lead to calamitous consequences.

The term “ECDIS assisted Grounding” has not arisen from nowhere, and based on our experience, recurrent themes often include the following:

Improper use of charts: i.e. not using or having the necessary charts for the intended voyage or not applying chart updates frequently and correctly
Not following or being aware of the manufacturer’s software maintenance updates and not updating the ECDIS to be compatible with the latest version of the IHO Standards.
Improper use of safety settings and built-in safeguards such as route checking and safety alarms related to depths.
Improper display settings, filters and scale.
Not using the route checking function at all or not using it with an appropriate Cross Track Distance (XTD). Not visually checking the route at an appropriate scale.
Lack of familiarity with the specific ECDIS type onboard.
Over-reliance on ECDIS and the displayed GPS position.
Inability to use or lack of familiarity with manual position fixing functions such as range and bearings.
Handover between deck officers including ECDIS-related information.

When Cross Track Distances are properly set to each leg of a voyage plan then route checking assists in checking for potential obstructions, dangers and insufficient depths.

When fitted, ECDIS must be type approved, conform to the relevant IMO performance standards, connect to an emergency source of electrical power, and have at least gyrocompass, speed log and GPS receiver inputs.

The system must have up-to-date Electronic Nautical Charts (ENC), or Raster Navigation Charts (RNC) where ENCs are not available or of an appropriate scale.

All nautical charts for the intended voyage(s) must be installed and maintained to be compatible with the latest applicable International Hydrographic Organization (IHO) chart content and display standards. Backup arrangements must be available, which can be either a secondary type-approved ECDIS or official, up-to-date paper charts.

Beyond the aforesaid general requirements of a SOLAS-compliant ECDIS, shipowners and operators are encouraged to undertake regular risk assessments of ECDIS navigation, including potential over-reliance of the system and improper use of the safety settings.

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ECDIS has become the essential tool for watchkeeping officers on ships. Navigating a ship with an ECDIS is fundamentally different from navigating with paper charts. It is important that the Masters, navigating officers, and ship-owners are aware of the benefits of managing the chart display, safety settings, and alarm system of ECDIS.

ECDIS equipped vessels have been involved in a number of groundings which may have been avoided had it not been for failures in the setup and use of ECDIS safety settings and alarm systems. Inappropriate settings are likely to render the safety contour alarms meaningless. The use of ECDIS safety settings has often been overlooked by navigating officers due to either ignorance or insufficient knowledge. Deck officers may be unfamiliar with the setup and use of ECDIS alarms thereby increasing the risk of grounding in shallow waters and causing other unwanted situations.

Related Read: Real Life Accident: Improper Use Of ECDIS Leads To Vessel Grounding

Appropriate safety settings are of paramount importance for ECDIS display. These settings control how the ECDIS presents depth information, making it easier to visualize areas of water that are safe for the vessel to navigate in from those which are not.

This article will help to understand the best practice for handling safety settings on ECDIS which includes the Safety contour, safety depth, shallow contour, and deep water contour. The model of ECDIS used for illustrations is Furuno.

Related Read: Pros and Cons of ECDIS Or Paperless Navigation Of Ships

These values can be entered in Furuno ECDIS by following the steps mentioned below:

  1. Go to the main menu and select Chart display
  2. Select the Main Tab to display it.

Safety Contour:

The safety contour is the most important parameter of all the safety settings for the display of unsafe water areas, detecting isolated dangers and triggering anti-grounding alarms. The safety contour is basically an outline which marks the division between safe and unsafe waters.

Related Read: Ship Stability – Understanding Intact Stability of Ships

The colour blue is used to indicate the unsafe areas while white or grey for safe areas.  The default safety contour if not specified by the mariner is set to 30m.  The blue colour in a traditional paper chart does not provide a vivid picture of shallow water, i.e the depths mentioned in the blue part of a paper chart may be shallower for a deep draft vessel while safe for a vessel with a smaller draft. Unlike paper charts ECDIS allows the officer to set safety parameters according to the ship’s static or dynamic particulars. The safety contour can be calculated as follows:

SAFETY CONTOUR = SHIP’S DRAFT + SQUAT + UKC – HEIGHT OF TIDE

Let us check an example.

Ship’s draft = 10 m

Let us consider that as per company policy UKC requirement is 10%. Please note that UKC calculation takes into account various factors such as sea conditions, density or increase in the draft due to rolling. It should be calculated as per company UKC calculation sheet.

UKC = 1.0m

Consider SQUAT AT MAX SPEED = 1 m

Height of tide = 1 m

Safety contour value would, therefore, be equal to 11 m.

Contours are present in the values of 5, 10, 15, 20, and 30 and so on. If the value set by the mariner is not available among the available depth contours, ECDIS selects the next deepest available contour in the ENC.

Related Read: What are the Methods To Update Navigation Charts On Board Ships?

If within a specified time set by the user, the ship is about to cross the safety contour, an alarm will sound. Based on the value of safety contour, ECDIS displays the isolated danger symbol for underwater features and obstructions which may pose a danger to navigation. The Isolated Danger Symbol is displayed if any underwater feature like wrecks, rocks or other obstructions has a depth less than the safety contour in waters beyond the safety contour.

Related Read: When Should Officer on Watch (OOW) Call the Ship’s Master?

Safety Depth Setting:

The sole purpose of the safety depth is to portray spot soundings either in gray for deeper depths or black for shallower depths compared to the safety depth value entered by the navigating officer thereby highlighting the potentially safe and unsafe areas. The safety depth value has no effect on alarms or any other aspect of ECDIS. Safety depth is normally the ship’s draft + squat.

Related Read: How Squat, Bank and Bank Cushion Effects Influence Ships?

Now the question is why do we need to mention safety depth when safety contour can demarcate between safe and unsafe waters? It is also logically to select Safety Depth equal to Safety Contour.

Some soundings on the shoaler side of the safety contour will be gray because they are deeper than the safety depth set by the mariner, although shoaler than the safety contour selected by ECDIS. The depths below safety contour may not always be non-navigable. Suppose for example if safety depth and safety contour are set to 11 m, the ECDIS will emphasize the depth contour equal or deeper than the selected contour which say is 20m, whichever is available in the ENC.

Related Read: How ECDIS Can Be Further Improved – A 2nd Officer’s Perspective

Thus we can see that water areas with depths between 11m to 20 m are navigable but are below the safety contour. This provides the mariner with additional information about where the ship could most safely pass if crossing the safety contour is required (an alarm will still sound). This could provide additional maneuvering room in narrow passages where safe depths exist.

There is also a possibility that depths shallower than the safety depth may exist at one point in the navigable waters. Safety depth setting will then highlight this danger.

In the picture above, safety depth value is 14m. You can see that depths equal to and below safety depth value are highlighted in bold.

Zone Of Confidence Catzoc:

In calculating safety depth it is also important to consider CATZOC features OR ZONE OF CONFIDENCE. We should be aware that much of the survey data displayed on ENCs derives from data that is many years old and hence cannot be relied upon completely for its authenticity. ZOC is used to determine the accuracy of the underlying hydrographic data. This is available in six categories. It enables the mariner to make sensible decisions on the degree of reliance to place on the chart when planning a passage or conducting navigation.

Let us consider an example.

Ship’s draft = 7.7m

Squat = 1m

Effective draft = 8.7m

Required company UKC is 10% of the deepest draft which is 0.87 approximately 0.9m.

Thus we see that the total safety depth required complying with company UKC policy is 9.6m. Safety depth value can be set as 10m. However, we haven’t yet considered the depth accuracy as per ZOC.  Let us consider that Catzoc in this area is category B which implies there can be an error of 1m + 2% of depth = 1.2m. Therefore if catzoc error is allowed, the minimum depth required would be 10m + 1.2m = 11.2m.  As safety depth cannot be entered in decimals in ECDIS, we can enter 12 m as safety depth. During passage planning, it is essential that CATZOC is displayed and noted for all stages of the voyage.

Catzoc Category B

Shallow Contour:

The shallow contour highlights the gradient of the seabed. It is considered to be the grounding depth i.e this is the depth below which the ship will definitely go aground. This value can be set equal to the ship’s draft. Therefore if ship’s draft is 7.7m, shallow contour value can be set as 8m. The ECDIS will then display the next depth contour available in the ENC. All of the areas between the 0m depth and the shallow contour is therefore not navigable at all and appears hatched. As I have already mentioned earlier that the division between safe and unsafe water is highlighted by chart colouring, with blue colour for indicating unsafe area while white or grey for safe areas. The unsafe area is further defined with the selection of shallow contour showing dark blue in the shallow water and light blue between the shallow water and the safety contour when 4 shade display is selected. 2 shade and 4 shade display is further explained below.

Related Read: Why Virtual Aids of Navigation Are Important For Ships?

Deep Water Contour Setting:

This is normally set to twice the ship’s draft. However navigating officers can use deep water contour value the way they want.

ECDIS also gives the option of simple two colour shading. In this situation light blue and deep blue will merge into a single blue colour and grey and white will merge to a single white colour. If the value of the safety contour is changed, the boundary between two depth shades changes accordingly. Two depth shades can be used during night time with caution to reduce the contrast difference between adjacent depth areas.

The picture above shows that the four shade depth option is not selected.

The pictures below show a comparison between two shade and four shade depth in daytime and night time.

Day Time

Night Time

Watch Vector/Anti Grounding Function:

The look ahead or watch vector actually compares the safety settings that have been entered by the navigating officer with the depth information contained in the ENC, and generates an indication or warning where the safety settings will be contravened. It provides advance warning of dangers/cautions, primarily intended to prevent grounding. It acts as a final layer of safety should a navigational danger be missed by the visual check or route scan. The scanned area is sometimes displayed as a cone or column on screen and should be set to a distance appropriate to the amount of navigable water ahead of the vessel. This value should be determined for each stage of the voyage and noted in the passage plan. Many officers fail to realize the significance of the safety contour and do not make proper use of the look-ahead vector.

This is how you can activate own ship check-in Furuno ECDIS.

  1. Go to Chart menu and select Initial Settings
  1. Open the menu displayed at the left and choose Chart Alert Parameters
  1. Click the Check area tab.
  2. Set Ahead Time or Ahead distance
  3. The Around field allows the officer to set fixed areas.

Note that the chart alert always uses the largest scale chart available, which may not be the visualized chart.

Note that the ‘Chart Alert’ feature should be highlighted so as to trigger the audible alarm whenever safety contour is breached.

It is required to amend the alarm parameters from their previous settings when beginning a new voyage. The alarm parameters need adjustments throughout the voyage to ensure they are optimized for the prevailing circumstances and conditions. ECDIS is a valuable asset in assisting navigators and providing them with more detailed situational awareness.  However, until used accurately and properly, ECDIS may contribute to accidents rather than preventing them.

Related Read: How to Order Electronic Navigation Charts and Keep Them Updated On Ships?

Increased training and practical use will help to develop and create a better ECDIS mindset. Trainee officers should be encouraged to understand the benefits that Ecdis provide and make the optimum use of the same. During route planning, a chart alert calculation should be done to detect any dangerous situation and the same should be modified as necessary. A better understanding of ECDIS safety settings and their proper use can act as a potential barrier to the grounding of ships and any untoward situation.

Disclaimer: The authors’ views expressed in this article do not necessarily reflect the views of Marine Insight. Data and charts, if used, in the article have been sourced from available information and have not been authenticated by any statutory authority. The author and Marine Insight do not claim it to be accurate nor accept any responsibility for the same. The views constitute only the opinions and do not constitute any guidelines or recommendation on any course of action to be followed by the reader.

The article or images cannot be reproduced, copied, shared or used in any form without the permission of the author and Marine Insight. 

 

Podcast #21: Heading for change – ECDIS safety and user interaction

For safe use of ECDIS it is important to consider standardisation and familiarisation, the need for continual training, the developments underway, and the trust that is placed in this heavily relied on aid to navigation.

Our podcast guest for this episode is Rob Gale, who is a former deck officer and has worked as a senior instructor for IMO approved ECDIS courses. Rob has also participated at the IMO in the working group for ECDIS standardisation.

Listen-in to gain some useful insights from Rob’s expert knowledge! 

LISTEN TO THE PODCAST EPISODE>>

1:36 The interview begins
2:45 Benefits of ECDIS
6:10 ECDIS standardisation
8:57 User friendliness and deeper knowledge about how ECDIS works
13:14 Divided opinions about ECDIS
16:58 Common user errors
22:43 The culture on board
25:10 Opinions and user feedback
28:21 The development of S-100
32:36 The risk of cognitive overload
36:12 Top three takeaways for managers & operators

 

Danielle Centeno, Asst. VP, Loss Prevention & Survey Compliance, American Club, analysed the “risks of a paperless chart system and incidents resulting from the improper use of ECDIS‎“ during her presentation at the 2016 SAFETY4SEA Conference & Awards. With the roll-out of the ECDIS requirements still underway there will be more vessels embracing electronic navigational charts as the primary means of navigation over a paper chart system. In his presentation, Mr Centeno explored three different grounding incidents resulting from the improper use of ECDIS‎ equipment and identified the risks associated with implementing these technologies.

There are many benefits of having ECDIS onboard; but also there are risks involved with complacency and over-reliance that we cannot ignore.  The mandatory carriage of ECDIS systems for ships on international voyages is still in implementation phase until July 2018. Firstly, it is important to identify the risks that are associated with the ECDIS system and over-reliance on them, before full implementation. The following incidents showcase the risks of a paperless chart system due to the improper use of ECDIS‎ equipment.

INCIDENT # 1

The vessel was fitted with ECDIS at the time it was built in order to comply with the IMO and flag state requirements for tankers. The passage plan from Rotterdam to Brindisi Italy was prepared, using the ECDIS Passage Planning feature, by the vessel’s third mate who had just been promoted to second mate/ navigational officer. The Course line drawn passed directly over the Varne Bank and included a passage through the Dover straits; a confined and heavy traffic area with a number of navigational hazards. The Master failed to review and approve this passage plan prior to departure. 

• The vessel’s primary means of navigation was an electronic chart display system (ECDIS). No paper charts were carried on board as the ECDIS was backed up with a duplicate system.

• The deck officers had received generic ECDIS training and certification as well as type specific training but made two significant errors in executing the passage plan electronically:

  1. In laying the course line over the Varne Bank the third officer used a scale of Chart too small (covering too large of an area) to show the sufficient water depths and buoy marker details. The ECDIS auto select function designed to warrant correct chart selection had been disabled.
  2. When the third officer conducted the automated hazard detection or “check route function” to determine if any navigational hazards existed on the plan he created he was not able to interpret the several hazard warnings that were listed including the Varne Bank. It was later found that none of the officers onboard knew how to properly use this function.

INCIDENT # 2

This incident deals with the authorized charts versus the unauthorized charts. In this incident the vessel had a passage plan prepared on paper charts initially. For this voyage the Passage plan was originally prepared on paper charts which were approved by the Master. The waypoints were then transferred to the Electronic Chart System.  The tracks were later changed as a result of weather routing faced during the voyage, but never examined by the Master.  

This vessel was fitted with an approved ECDIS model but was not supplied with “official” electronic navigation charts required to meet acceptance standards for an Electronic Chart Display and Information System (ECDIS).  Without installation of official charts the setup could only be considered an Electronic Chart System (ECS). While it can display nautical chart data and vessel position on a screen it does not satisfy SOLAS Chapter V requirements and may be used only as an aid to navigation.

Official Electronic Navigational Charts must be:

  1. Produced and issued by an authority of government or relevant institution or an authorized Hydrographic Offices such as NOAA, British Admiralty, Etc.
  2. Used in all acceptable ECDIS training courses

Other types of unofficial electronic charts, for example charts produced by private industry or raster charts, can only be used as a supplement for navigation and may

  • Use a different chart symbology then what is listed in IHO Special Publication No. 52 Specifications for Chart content and display aspects of ECDIS.
  • Produce less frequent or irregular chart updates, as opposed to weekly updates for official charts.
  • Have unknown or less stringent standards for digital hydrographic data transfer and production while official sources are governed by IHO to ensure accuracy and quality.

INCIDENT #3

The third officer had altered the vessel’s course to starboard of the planned track to avoid another motor vessel and sailing vessel. The course alterations which were initiated too prematurely which took the vessel into shallow waters. The ECDIS anti-grounding warning ‘zone alarm’ activated on the electronic chart display, but went unnoticed by the third mate, who was not monitoring the ECDIS display. In this case the anti-grounding safety function “audible alarm” did not sound.

Some common themes in these three incidents were:

1. ECDIS was used as the primary means of navigation

The vessels had ECDIS installed as the primary means of navigation and is considered “Paperless”. The primary method for navigation may be ECDIS but a backup is required in the event of a failure. The backup can either be a secondary ECDIS (known as a dual system) connected to an independent power supply and GPS position input or the traditional paper charts.

2. The ships officers had completed generic ECDIS training

The Navigation officers had received the general IMO Mandated (or equivalent) ECDIS training however Masters and Officers are not required to be trained in accordance with the new competence standards until 1 January 2017 to meet the 2010 Manila Amendments. Generic training for vessels equipped with ECDIS (for example, the IMO model course 1.27) is suggested in the regulations.

Equipment-specific training must be carried out in accordance with the Vessels to the Safety Management System as per the International Safety Management (ISM) Code.

3. Mistakes made by the navigating officers went undetected by Master

The Vessel’s junior officers were responsible for the passage planning or navigating errors but the Vessel Masters failed to recognize the lack of proficiency in his watch officers and failed to provide adequate supervision in every situation.

ECDIS Capabilities and Limitations

ECDIS Features and Alarms: Most ECDIS’s come with safety features and warnings which may or may not trigger an audible alarm. There is also a risk of silencing more common alarms or setting depth safety parameters improperly

Accuracy of charts: While receiving official data is important hydrographic offices despite their best efforts are not always exactly replicating real life.  Navigating through an area which is poorly surveyed, or unsurveyed, regardless of what’s shown on the chart, will have considerable risk of being there in the first place. It’s important to check the chart source data diagram or Category Zones of Confidence, CATZOCs, to see just how reliable the chart, whether paper or electronic. ECDIS isn’t necessarily going to be more accurate than paper.

Training and Competency of the Navigational Officers: The IMO Model Course 1.27 on the Operational Use of Electronic Chart Display and Information Systems is regarded as a minimum requirement to receive an ECDIS certificate. Despite over 33 models of ECDIS equipment on the market, there is currently no mandatory requirement for bridge officers to receive ECDIS model or type specific training.  The Master must oversee and approve the passage plan, and must stress the importance of contacting him when the mates are in doubt.

Foreseeable trends and risks

1. Over-Reliance

The importance of keep a proper visual look out must not be overlooked. Also, it is very important to go through the company’s procedures in the event of ECDIS failure. Radar Plotting, Sights, Compass Errors will come in handy in the event of an ECDIS breakdown.

2. Improper Settings

There is a risk of setting the wrong safety parameters for Depths, Safety Contours and navigation warnings. It is extremely important that the Master himself checks these settings each time they are changed. Alarms should not be deactivated without a good reason for doing so and never just for the sake of avoiding frequent alarms.

You may reduce the risk of these errors by implementing procedures for password protecting ECDIS setting and properly documenting parameter changes or silenced alarms.

3. Alarm Deafness

When alarms start going off too frequently, the navigator could form a dangerous habit called Alarm Deafness. This leads to the watch keeper acknowledging the alarm even without checking what it was.

4. Different Manufactures

With all different types of ECDIS machines, type specific training is being required by many flag states prior to coming onboard.  It is not always easy to get all of the officer’s type-specific training especially if there is a need to embark on short notice.

Some companies have decided to select a single Equipment manufacturer to supply the company’s fleet with ECDIS equipment, which can ease the training burden of a company considerably.

5. Anomalies

As we saw in incident No.1, there may be instances where anomalies occur such as the depth markers or navigation symbols not appearing when a certain chart scale is in use.  When it comes to electronic navigation even more emphasis must be made on understanding the nuances of your ECDIS system entirely.

An emphasis on practical navigation should always be in mind. A good example is “US Naval academy reinstates celestial navigation” which concerns with cyber-attacks and GPS jamming devices and are now easily obtained in the civilian market.

Above text is an edited article of Danielle Centeno’s presentation during the 2016 SAFETY4SEA Conference & Awards

You may view her video presentation by clickinghere

The views presented hereabove are only those of the author and not necessarily those of  SAFETY4SEA and are for information sharing and discussion  purposes only.

[divider]

Danielle Centeno, Asst. VP, Loss Prevention & Survey Compliance, American Club

danielle-centeno_Danielle Centeno joined the Shipowners Claims Bureau, Inc., managers of the American P&I Club in November of 2015 as Assistant Vice President of Loss Prevention & Survey Compliance. She is a certified ISM Internal Auditor and a graduated from the New York Maritime College at Fort Schuyler in 2007 with a Bachelor of Science degree in Marine Transportation. Early in her career, she sailed as a third mate on general cargo ships for the U.S. merchant navy.  Thereafter, Danielle worked at Bouchard Transportation Company as lead internal auditor as well as safety, quality and vetting coordinator.  Following that she served as Company Security Officer and Designated Person Ashore for Sealift Inc. of Oyster Bay, New York.  She is currently a lieutenant in the United States Navy Reserve.

Tags:ECDISSAFETY4SEA

That: Common ecdis use errors

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common ecdis use errors

Danielle Centeno, Asst. VP, Loss Prevention & Survey Compliance, common ecdis use errors, American Club, analysed the “risks of a paperless chart system and incidents resulting from the improper use of ECDIS‎“ during her presentation at the 2016 SAFETY4SEA Conference & Awards. With the roll-out of the ECDIS requirements still underway there will be more vessels embracing electronic navigational charts as the primary means of navigation over a paper chart system. In his presentation, Mr Centeno explored three different grounding incidents resulting from the improper use of ECDIS‎ equipment and identified the risks associated with implementing these technologies.

There are many benefits of having ECDIS onboard; but also there are risks involved with complacency and over-reliance that we cannot ignore.  The mandatory carriage of ECDIS systems for ships on international voyages is still in implementation phase until July 2018. Firstly, it is important to identify the risks that are associated with the ECDIS system and over-reliance on them, before full implementation. The following incidents showcase the risks of a paperless chart system due to the improper use of ECDIS‎ equipment.

INCIDENT # 1

The vessel was fitted with ECDIS at the time it was built in order to comply with the IMO and flag state requirements for tankers. The passage plan from Rotterdam to Brindisi Italy was prepared, using the ECDIS Passage Planning feature, by the vessel’s third mate who had just been promoted to second mate/ navigational officer. The Course line drawn passed directly over the Varne Bank and included a passage through the Dover straits; a confined and heavy traffic area with a number of navigational hazards. The Master failed to review and approve this passage plan prior to departure. 

• The vessel’s primary means of navigation was an electronic chart display system (ECDIS). No paper charts were carried on board as the ECDIS was backed up with a duplicate system.

• The deck officers had received generic ECDIS training and certification as well as type specific training but made two significant errors in executing common ecdis use errors passage plan electronically:

  1. In laying the course line over the Varne Bank the third officer used a scale of Chart too small (covering too large of an area) to show the sufficient water depths and buoy marker details. The ECDIS auto select function designed to warrant correct chart selection had been disabled.
  2. When the third officer conducted the automated hazard detection or “check route function” to determine if any navigational hazards existed on the plan he created he was not able to interpret the several hazard warnings that were listed including the Varne Bank. It was later found that none of the officers onboard knew how to properly use this function.

INCIDENT # 2

This incident deals with the authorized charts versus the unauthorized charts. In this incident the vessel had a passage plan prepared on paper charts initially. For this voyage the Passage plan was originally prepared on paper charts which were approved by the Master, common ecdis use errors. The waypoints were then transferred to the Electronic Chart System.  The tracks were later changed as a result of weather routing faced during the voyage, but never examined by the Master.  

This vessel was fitted with an approved ECDIS model but was not supplied with “official” electronic navigation charts required to meet acceptance standards for an Electronic Chart Display and Information System (ECDIS).  Without installation of official charts the setup could only be considered an Electronic Chart System (ECS). While it can display nautical chart data common ecdis use errors vessel position on a screen it does not satisfy SOLAS Chapter V requirements and may be used only as an aid to navigation.

Official Electronic Navigational Charts must be:

  1. Produced and issued by an authority of government or relevant institution or an authorized Hydrographic Offices such as NOAA, British Admiralty, Etc.
  2. Used in all acceptable ECDIS training courses

Other types of unofficial electronic charts, for example charts produced by private industry or raster charts, can only be used as a supplement for navigation and may

  • Use a different chart symbology then what is listed in IHO Special Publication No. 52 Specifications for Chart content and display aspects of ECDIS.
  • Produce less frequent or irregular common ecdis use errors updates, common ecdis use errors, as opposed to weekly updates for official charts.
  • Have unknown or less stringent standards for digital hydrographic data transfer and production while official sources are governed by IHO to ensure accuracy and quality.

INCIDENT #3

The third officer had altered the vessel’s course to starboard of the planned track to avoid another motor common ecdis use errors and sailing vessel. The course alterations which were initiated too prematurely which took the vessel into shallow waters. The ECDIS anti-grounding warning ‘zone alarm’ activated on the electronic chart display, but went unnoticed by the third mate, who was not monitoring the ECDIS display. In this case the anti-grounding safety function “audible alarm” did not sound.

Some common themes in these three incidents were:

1. ECDIS was used as the primary means of navigation

The vessels had ECDIS installed as the primary means of navigation and is considered “Paperless”. The primary method for navigation may be ECDIS but a backup is required in the event of a failure. The backup can either be a secondary ECDIS (known as a dual system) connected to an independent power supply and GPS position input or the traditional paper charts.

2. The ships officers had completed generic ECDIS training

The Navigation officers had received the general IMO Mandated (or equivalent) ECDIS training however Masters and Officers are not required to be trained in accordance with the new competence standards until 1 January 2017 to meet the 2010 Manila Amendments. Generic training for vessels equipped with ECDIS (for example, common ecdis use errors, the IMO model course 1.27) is suggested in the regulations.

Equipment-specific training must be carried out in accordance with the Vessels to the Safety Management System as per the International Safety Common ecdis use errors (ISM) Code.

3. Mistakes made by the navigating officers went undetected by Master

The Vessel’s junior officers were responsible for the passage planning or navigating errors but the Vessel Masters failed to recognize the lack of proficiency in his watch officers and failed to provide adequate supervision in every situation.

ECDIS Capabilities and Limitations

ECDIS Features and Alarms: Most ECDIS’s come with safety features and warnings which may or may not trigger an audible alarm. There is also a risk of silencing more common alarms or setting depth safety parameters improperly

Accuracy of charts: While receiving official data is important hydrographic offices despite their best efforts are not always exactly replicating real life.  Navigating through an area which is poorly surveyed, or unsurveyed, regardless of what’s shown on the chart, will have considerable risk of being there in the first place. It’s important to check the chart source data diagram or Category Zones of Confidence, CATZOCs, to see just how reliable common ecdis use errors chart, whether paper or electronic. ECDIS isn’t necessarily going to be more accurate than paper.

Training and Competency of the Navigational Officers: The IMO Model Course 1.27 on the Operational Use of Electronic Chart Display and Information Systems is regarded as a minimum requirement to receive an ECDIS certificate. Despite over 33 models of ECDIS equipment on the market, there is currently no mandatory requirement for bridge officers to receive ECDIS model or type specific training.  The Master must oversee and approve the passage plan, and must stress the importance of contacting him when the mates are in doubt.

Foreseeable trends and risks

1. Over-Reliance

The importance of keep a proper visual look out must not be overlooked. Also, common ecdis use errors, it is very important to go through the company’s procedures in the event of ECDIS failure. Radar Plotting, Sights, Compass Errors will come in handy in the event of an ECDIS breakdown.

2. Improper Settings

There is a risk of setting the wrong safety parameters for Depths, Safety Contours and navigation warnings. It is extremely important that the Master himself checks these settings each time they are changed. Alarms should not be deactivated without a good reason for doing so and never just for the sake of avoiding frequent alarms.

You may reduce the risk of these errors by implementing procedures for password protecting ECDIS setting and properly documenting parameter changes or silenced alarms.

3. Alarm Deafness

When alarms start going off too frequently, the navigator could form a dangerous habit called Alarm Deafness. This leads to the watch keeper acknowledging the alarm even without checking what it was.

4. Different Manufactures

With all different types of ECDIS machines, type specific training is being required by many flag states prior to coming onboard.  It is not always easy to get all of the officer’s type-specific training especially if there is a need to embark on short notice.

Some companies have decided to select a single Equipment manufacturer to supply the company’s fleet with ECDIS equipment, which can ease the training burden of a company considerably.

5. Anomalies

As we saw in incident No.1, there may be instances where anomalies occur such as the depth markers or navigation symbols not appearing when a certain chart scale is in use.  When it comes to electronic navigation even more emphasis must be made on understanding the nuances of your ECDIS system entirely.

An emphasis on practical navigation should always be in mind. A good example is “US Naval academy reinstates celestial navigation” which concerns with cyber-attacks and GPS jamming devices and are now easily obtained in the civilian market.

Above text is an edited article of Danielle Centeno’s presentation during the 2016 SAFETY4SEA Conference & Awards

You may view her video presentation by clickinghere

The views presented hereabove are only those of the author and not necessarily those of  SAFETY4SEA and are for information sharing common ecdis use errors discussion  purposes only.

[divider]

Danielle Centeno, Asst, common ecdis use errors. VP, Loss Prevention & Survey Compliance, American Club

danielle-centeno_Danielle Centeno joined the Shipowners Claims Bureau, Inc., managers of the American P&I Club in November of 2015 as Assistant Vice President of Loss Prevention & Survey Compliance. She is a certified ISM Internal Auditor and a graduated from the New York Maritime College at Fort Schuyler in 2007 with a Bachelor of Science degree common ecdis use errors Marine Transportation. Early in her career, she sailed as a third mate on general cargo ships for the U.S. merchant navy.  Thereafter, Danielle worked at Bouchard Transportation Company as lead internal auditor as well as safety, common ecdis use errors, quality and vetting coordinator.  Following that she served as Company Security Officer and Designated Person Ashore for Sealift Inc. of Oyster Bay, New York.  She is currently a lieutenant in the United States Navy Reserve.

Tags:ECDISSAFETY4SEA

Best practices to avoid 7 of the common marine navigation mistakes that can lead to accidents

A vessel was in transit through the Suez Canal with a pilot on board. The vessel was supposed to move along the centerline of the canal, however, as it deviated from the center line, the pilot and the crew on the bridge used the corrective wheel and thrusters to counteract this deviation. By that time, common ecdis use errors, the ship had swung heavily and approached the bank on the opposite side. The stern of the vessel touched the rocky sea bottom. There was a heavy thud and a vibration in the wheelhouse and engine room. The ship's speed dropped and increased again. All common ecdis use errors crew noticed the vibration. The engine room called the bridge to confirm that everything was in order. Both watches confirmed to the pilot if everything was in order, to which the pilot replied in the affirmative. The vessel picked up speed again and resumed movement along the canal. The most senior officer of the watch did not call the captain and did not discuss the incident with him later. However, below the waterline, common ecdis use errors, the bow of the hull was damaged and its strength in the impacted zone was significantly reduced. There was a slight deformation, but below the waterline. Later when the ship was loading the cargo at port, common ecdis use errors, there was again a big dull sound, and the OOW noticed that water gushed into the ballast tanks No, common ecdis use errors. 1, 2, 3 at the port side. Due to the constant stress on the damaged, deformed and worn plate, the weak zone collapsed and failed.

Often we have seen junior officers on board ships respond "Yes, sir" to any given task, and later find that something else has been done about the subject.

Various incidents on board require the seafarer to act and react according to predefined and predetermined 508 error code during routine and common ecdis use errors situations. For a variety of non-standard tasks, common ecdis use errors, companies have also introduced procedures for group meetings, on board common ecdis use errors and risk assessments. These interactions help the captain or other team leaders recognize the merits and weaknesses of their team members before assigning a task. Communication between the team leader and team members, or between team members, is key here in avoiding the occurrence of human error chains by identifying and eliminating their root causes.

Strengthen the communication between crew members

Podcast #21: Heading for change – ECDIS safety and user interaction

For safe use of ECDIS it is important to consider standardisation and familiarisation, the need for continual training, the developments underway, and the trust that is placed in this heavily relied on aid to navigation.

Our podcast guest for this episode is Rob Gale, who is a former deck officer and has worked as a senior instructor for IMO approved ECDIS courses. Rob has also participated at the IMO in the working group for ECDIS standardisation.

Listen-in to gain some useful insights from Rob’s expert knowledge! 

LISTEN TO THE PODCAST EPISODE>>

1:36 The interview begins
2:45 Benefits of ECDIS
6:10 ECDIS standardisation
8:57 User friendliness and deeper knowledge about how ECDIS works
13:14 Divided opinions about ECDIS
16:58 Common user errors
22:43 The culture on board
25:10 Opinions and user feedback
28:21 The development of S-100
32:36 The risk of cognitive overload
36:12 Top three takeaways for managers & operators

 

Numerous groundings and near misses have occurred on ECDIS equipped ships that could have been avoided but for failures in the setup and use of ECDIS. Like most of the world’s merchant fleet trading internationally, your ship(s) is most likely equipped with an Electronic Chart System (ECS) or Electronic Chart Display and Information System (ECDIS). Maybe it is fully compliant with the IMO requirements for an ECDIS and therefore the primary means of navigation, or perhaps you are still transitioning towards an approved system.

The primary function of ECDIS is to enhance the safety of navigation, but experience is showing that installation and approval alone are not enough to achieve this goal. Comprehensive training, including type-specific familiarisation, and updated Safety Management Common ecdis use errors (SMS) procedures are essential to ensure safe ECDIS use without introducing new risk.

Furthermore, Port State Control Authorities have reported an increase in deficiencies concerning ECDIS use following Concentrated Inspection Campaigns (CIC) on safe navigation. The age of e-Navigation is firmly upon us and the transition to electronic-based navigation is a fundamental shift away from the not-so-distant past where azimuth sights, sextants, and parallel rulers were the indispensable tools of every navigator.

A base ENC with limited chart information compared to the unfiltered chart of the same channel and location. Overuse or improper use of filters and contours may result in ambiguous displays of soundings and potentially dangerous interpretations.

Risk Factors

Everything a ship’s officer can do on a paper chart must be feasible on an ECDIS device; i.e. a functional equivalent. This includes the most basic of navigation tasks such as manually plotting the ship’s position by range and bearing; thorough passage planning, including voyage notes and callouts; marking of nogo areas; applying manual chart corrections … and so on. The reality is, ECDIS can do all this and a whole lot more.

Modern ECDIS systems are now so functional that inadvertent actions or settings may be applied, which can then go unnoticed. Safety contour and safety depth functions, for instance, may be misused rendering common ecdis use errors alarm meaningless. Display settings may reduce the visibility of essential information from the screen as previously shown.

Position data and/or reference points may have unwanted offsets – for instance, when was the last time the CCRP (Consistent Common Reference Point) settings were checked? Are they correct for multiple antennas and radar systems? Are the CCRP settings locked and password protected against accidental meddling?

Manual position plotting can be done quickly and easily on an ECDIS, but it is critical that officers familiarise and regularly practise this function.GPS positions should be cross-referenced using visual/ radar range and bearings.

Safety contour and safety depth settings can drastically affect the display and when alarms are common ecdis use errors width="419" height="419" src="https://www.knowledgeofsea.com/wp-content/uploads/2020/03/459.png" alt="">

The Safety Contour Depth should normally be set to the “Vessel Safety Draft,” which is commonly calculated as:

Vessel Safety Draft = Vessel Draft + Dynamic Squat + Safety Margin.

The Safety Contour marks the boundary between “safe-water” and shallow water and can be set to give an alarm if the ship is approaching the contour.

Consistent Common Reference Point settings and locations of antennas, radars and other reference points should be set correctly and frequently checked.

These are just a few of the unwelcome risks that may be introduced unintentionally if navigators are not properly trained and instructed in the correct use of the systems fitted aboard their ships.

Common operational mistakes

When properly operated, common ecdis use errors, ECDIS is an exceptional tool that drastically improves situational awareness and operational efficiency, and can reduce errors. On the other hand, over-reliance or lack of familiarity can lead to calamitous consequences.

The term “ECDIS assisted Grounding” has not arisen from nowhere, and based on our experience, recurrent themes often include the following:

Improper use of charts: i.e. not using or having the necessary charts for the intended voyage or not applying chart updates frequently and correctly
Not following or being aware of the manufacturer’s software maintenance updates and not updating the ECDIS to be compatible with the latest version of the IHO Standards.
Improper use of safety settings and built-in safeguards such as route checking and safety alarms related to depths.
Improper display settings, common ecdis use errors, filters common ecdis use errors scale.
Not using the route checking function at all or not using it with an appropriate Cross Track Distance (XTD). Not visually checking the route at an appropriate scale.
Lack of familiarity with the specific ECDIS type onboard.
Over-reliance on ECDIS and the displayed GPS position.
Inability to use or lack of familiarity with manual position fixing functions such as range and bearings.
Handover between deck officers including ECDIS-related information.

When Cross Track Distances are properly set to each leg of a voyage plan then route checking assists in checking for potential obstructions, dangers and insufficient depths.

When fitted, ECDIS must be type approved, conform to the relevant IMO performance standards, connect to an emergency source of electrical power, and have at least gyrocompass, speed log and GPS receiver inputs.

The system must have up-to-date Electronic Nautical Charts (ENC), or Raster Navigation Charts (RNC) where ENCs are not available or of an appropriate scale.

All nautical charts for the intended voyage(s) must be installed and maintained to be compatible with the latest applicable International Hydrographic Organization (IHO) chart content and display standards. Backup arrangements must be available, which can be either a secondary type-approved ECDIS or official, up-to-date paper charts.

Beyond the aforesaid general requirements of a SOLAS-compliant ECDIS, shipowners and operators are encouraged to undertake regular risk assessments of ECDIS navigation, including potential over-reliance of the system and improper use of the safety settings.

Tagged with:ecdis, ecdis common mistake

ECDIS has become the essential tool for watchkeeping officers on ships. Navigating a ship with an ECDIS is fundamentally different from navigating with paper charts. It is important that the Masters, navigating officers, and ship-owners are aware of the benefits of managing the chart display, safety settings, and alarm system of ECDIS.

ECDIS equipped vessels have been involved in a number of groundings which may have been avoided had it not been for failures in common ecdis use errors setup and use of ECDIS safety settings and alarm systems. Inappropriate settings are likely to render the safety contour alarms meaningless. The use of ECDIS safety settings has often been overlooked by navigating officers due to either ignorance or insufficient knowledge, common ecdis use errors. Deck officers may be unfamiliar with the setup and use of ECDIS alarms thereby increasing the risk of grounding in shallow waters and causing other unwanted situations.

Related Read: Real Life Accident: Improper Use Of ECDIS Leads To Vessel Grounding

Appropriate safety settings are of paramount importance for ECDIS display. These settings control how the ECDIS presents depth information, making it easier to visualize areas common ecdis use errors water that are safe for the vessel to navigate in from those which are not.

This article will help to understand the best practice for handling safety settings on ECDIS which includes the Safety contour, safety depth, shallow contour, and deep water contour. The model of ECDIS used for illustrations is Furuno.

Related Read: Pros and Cons of ECDIS Or Paperless Navigation Of Ships

These values can be entered in Furuno ECDIS by following the steps mentioned below:

  1. Go to the main menu and select Chart display
  2. Select the Main Tab to display it.

Safety Contour:

The safety contour is the most important parameter of all the safety settings for the display of unsafe water areas, detecting isolated dangers and triggering anti-grounding alarms. The safety contour is basically an outline which marks the division between safe and unsafe waters.

Related Read: Ship Stability – Understanding Intact Stability of Ships

The colour blue is used to indicate the unsafe areas while white or grey for safe areas.  The default safety contour if not specified by the mariner is set to 30m.  The blue colour in a traditional paper chart does not provide a vivid picture of shallow water, common ecdis use errors, i.e the depths mentioned in the blue part of a paper chart may be shallower for a deep draft vessel while safe for a vessel with a smaller draft. Unlike paper charts ECDIS allows the officer to set safety parameters according to the ship’s static or dynamic particulars. The safety contour can be calculated as follows:

SAFETY CONTOUR = SHIP’S DRAFT + SQUAT + UKC – HEIGHT OF TIDE

Let us check an example.

Ship’s draft = 10 m

Let us consider that as per company policy UKC requirement is 10%. Please note that UKC calculation takes into account various factors such as sea conditions, common ecdis use errors, common ecdis use errors or increase in the draft due to rolling. It should be calculated as per company UKC calculation sheet.

UKC = 1.0m

Consider SQUAT AT MAX SPEED = 1 m

Height of tide = 1 m

Safety contour value would, therefore, be equal to 11 m.

Contours are present in the values of 5, 10, 15, 20, and 30 and so on. If the value set by the mariner is not available among the available depth contours, ECDIS selects the next deepest available contour in the ENC.

Related Read: What are the Methods To Update Navigation Charts On Board Ships?

If within a specified time set by the user, the ship is about to cross the safety contour, an alarm will sound. Based on the value of safety contour, ECDIS displays the isolated danger symbol for underwater features and obstructions which may pose a danger to navigation. The Isolated Danger Symbol is displayed if any underwater feature like wrecks, common ecdis use errors, rocks or other obstructions has a depth less than the safety contour in waters beyond the safety contour.

Related Read: When Should Officer on Watch (OOW) Call the Ship’s Master?

Safety Depth Setting:

The sole purpose of the safety depth is to portray spot soundings either in gray for deeper depths or black for shallower depths compared to the safety depth value entered by the navigating officer thereby highlighting the potentially safe and unsafe areas. The safety depth value has no effect on alarms or any other aspect of ECDIS. Safety depth is normally the ship’s draft + squat.

Related Read: How Squat, Bank and Bank Cushion Effects Influence Ships?

Now the question is why do we need to mention safety depth when safety contour can demarcate between safe and unsafe waters? It is also logically to select Safety Depth equal to Safety Contour.

Some soundings on the shoaler side of the safety contour will be gray because they are deeper than the safety common ecdis use errors set by the mariner, although shoaler than the safety contour selected by ECDIS. The depths below safety contour may not always be non-navigable. Suppose for example if safety depth and safety contour are set to 11 m, the ECDIS will emphasize the depth contour equal or deeper than the selected contour which say is 20m, whichever is available in the ENC.

Related Read: How ECDIS Can Be Further Improved – A 2nd Officer’s Perspective

Thus we can see that water areas with depths between 11m to 20 m are navigable but are below the safety contour. This provides the mariner with additional information about where the ship could most safely pass if crossing the safety contour is required (an alarm will still sound). This could provide additional maneuvering room in narrow passages where safe depths exist.

There is also a possibility that depths shallower than common ecdis use errors safety depth may exist at one point in the navigable waters. Safety depth setting will then highlight this danger.

In the picture above, safety depth value is 14m. You can see that depths equal to and below safety depth value are highlighted in bold.

Zone Of Confidence Catzoc:

In calculating safety depth it is also important to consider CATZOC features OR ZONE OF CONFIDENCE. We should be aware that much of the survey data displayed on ENCs derives from data that is many years old and hence cannot be relied upon completely for its authenticity. ZOC is used to determine the accuracy of the underlying hydrographic data. This is available in six categories. It enables the mariner to make sensible decisions on the degree of reliance to place on the chart when planning a passage or conducting navigation.

Let us consider an example.

Ship’s draft = 7.7m

Squat = 1m

Effective draft = 8.7m

Required company UKC is 10% of the deepest draft which is 0.87 approximately 0.9m.

Thus we see that the total safety depth required complying with company UKC policy is 9.6m, common ecdis use errors. Safety depth value can be set as 10m. However, we haven’t yet considered the depth accuracy as per ZOC.  Let us consider that Catzoc in this area is category B which implies there can be an error of 1m + 2% of depth = 1.2m. Therefore if catzoc error is allowed, the minimum depth required would be 10m + 1.2m = 11.2m.  As safety depth cannot be entered in decimals in ECDIS, we can enter 12 m as safety depth. During passage planning, it is essential that CATZOC is displayed and noted for all stages of the voyage.

Catzoc Category B

Shallow Contour:

The shallow contour highlights the gradient of the seabed. It is considered to be the grounding depth i.e this is the depth below which the ship will definitely go aground. This value can be set equal to the ship’s draft, common ecdis use errors. Therefore if ship’s draft is 7.7m, shallow contour value can be set as 8m. The ECDIS will then display the next depth contour available in the ENC. All of the areas between the 0m depth and the shallow contour is therefore not navigable at all and appears hatched. As I have already mentioned earlier that the division between safe and unsafe water is highlighted by chart colouring, with blue colour for indicating unsafe area while white or grey for safe areas. The unsafe area is further defined with the selection of shallow contour showing dark blue in the shallow water and light blue between the shallow water and the safety contour when 4 shade display is selected, common ecdis use errors. 2 shade and 4 shade display is further explained below.

Related Read: Why Virtual Aids of Navigation Are Important For Ships?

Deep Water Contour Setting:

This is normally set to twice the ship’s draft. However navigating officers can use deep water contour value the way they want.

ECDIS also gives the option of simple two colour shading. In this situation light blue and deep blue will merge into a single blue colour and grey and white will merge to a single white colour, common ecdis use errors. If the value of the safety contour is changed, common ecdis use errors, the boundary between two depth shades changes accordingly. Two depth shades can be used during night time with caution to reduce the contrast difference between adjacent depth areas.

The picture above shows that the four shade depth option is not selected.

The pictures below show a comparison between two shade and four shade depth in daytime and night time.

Day Time

Night Time

Watch Vector/Anti Grounding Function:

The look ahead or watch vector actually compares the safety settings that have been entered by the navigating officer with the depth information contained in the ENC, and generates an indication or warning where the safety settings will be contravened. It provides advance warning of dangers/cautions, primarily intended to prevent grounding. It acts as a final layer of safety should a navigational danger be missed by the visual check or route scan. The scanned area is sometimes displayed as a cone or column on screen and should be set to a distance appropriate to the amount of navigable water ahead of the vessel. This value should be determined for each stage of the voyage and noted in the passage plan. Many officers fail to realize the significance of the safety contour and do not make proper use of the look-ahead vector.

This is how you can activate own ship check-in Furuno ECDIS.

  1. Go to Chart menu and select Initial Settings
  1. Open the menu displayed at the left and choose Chart Alert Parameters
  1. Click the Check area tab.
  2. Set Ahead Time or Ahead distance
  3. The Around field allows the officer to set fixed areas.

Note that the chart alert always uses the largest scale chart available, which may not be the visualized chart.

Note that the ‘Chart Alert’ feature should be highlighted so as to trigger the audible alarm whenever safety contour is breached.

It is required to amend the alarm parameters from their previous settings when beginning a new voyage. The alarm parameters need adjustments throughout the voyage to ensure they are optimized for the prevailing circumstances and conditions, common ecdis use errors. ECDIS is a valuable asset in assisting navigators and providing them with more detailed situational awareness.  However, until used accurately and properly, ECDIS may contribute to accidents rather than preventing them.

Related Read: How to Order Electronic Navigation Charts and Keep Them Updated On Ships?

Increased training and practical use will help to develop and create a better ECDIS mindset. Trainee officers should be encouraged to understand the benefits that Ecdis provide and make the optimum use of the same. During route planning, a chart alert calculation should be done to detect any dangerous situation and the same should be modified as necessary. A better understanding of ECDIS safety settings and their proper use can act as a potential barrier to the grounding of ships and any untoward situation.

Disclaimer: The authors’ views expressed in this article do not necessarily reflect the views of Marine Insight. Data and charts, if used, common ecdis use errors, in the article have been sourced from available information and have not been authenticated by any statutory authority. The author and Marine Insight do not claim it to be accurate nor accept any responsibility for the same. The views constitute only the opinions and do not constitute any guidelines or recommendation on any course of action to be followed by the reader.

The article or images cannot be reproduced, copied, shared or used in any form without the permission of the author and Marine Insight. 

 

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