An ECDIS is one of the essential tools of a modern navigator. This tool displays digital charts and other navigational information, which improves organization and efficiency compared to traditional nautical charts. To get the most out of your ECDIS, it's essential that you follow best practices.

It's easy to find guidelines on best practices, though, thanks to the International Maritime Organization. In June 2017, their dedicated safety committee released a guideline on best practices for ECDIS use. It contains a fairly comprehensive guide on using your ECDIS for navigation.

IMO Circular MSC.1/Circ.1503

IMO Circular MSC.1/Circ.1503, also known as ECDIS – Guidance for Good Practice, is a combination of several prior ECDIS circulars. Each of those documents dealt with a certain aspect of ECDIS use, and MSC.1/Circ.1503 provides a comprehensive guide on this field by merging them. The document is meant to help educate navigators, captains, deck officers, and other relevant personnel in the proper use of their ECDIS.

While the document emphasizes navigators and sailors, its relevance expands much further. Any field that relies upon ECDIS equipment should understand these guidelines. This includes VTS and SAR operators as well as those who man offshore installations.

The International Maritime Organization divided the document into seven sections plus three appendices. Chart Carriage Requirement of SOLAS is the first section, and it lays down performance standards for ECDIS units.

Chart Carriage Requirement of SOLAS

IMO Circular MSC.1/Circ.1503 defines two performance standards for ECDIS units and requires that any ECDIS unit must comply with one or the other, depending on when the original installation occurred. The IMO resolution A.817(19) and resolution MSC.232(82) elaborate on each of these standards. If a user is relying on their ECDIS to meet SOLAS charge carriage requirements, then the maritime standards entail the following requirements:

• An ECDIS must first go through type approval, which will certify it as compliant with IMO regulations
• The electronic nautical charts in use must be up to date
• The user must maintain their ECDIS in line with the latest standards as developed by the International Hydrographic Organization
• There must be sufficient preparation to replace the ECDIS in case of technical failure

SOLAS regulation V/19.2.1.4 states that ships must have all nautical charts necessary to complete their voyage before embarking. In the case of a ship that chooses to use ECDIS, it should carry the complete suite of electronic navigational charts. If it's impossible to fill the requirements with ENCs, then Raster Navigational Charts and paper charts are acceptable supplementary resources. To date, ENC coverage is not all encompassing across the world, so it's advisable to identify any areas that lack ENC coverage in advance. It's simple to verify adequate coverage thanks to the our primary e-Navigation software SPICA, where users can find a frequently updated chart catalog that details the coverage of electronic navigational charts.

One related standard is SOLAS regulation V/27, which states that ships must use up-to-date nautical charts. While Raster Charts and paper charts are acceptable, they must also be sufficiently recent as to be relevant and reliable. Additionally, the software on an ECDIS needs to remain in line with the latest IHO standards on displays and chart content.

Even when an ECDIS and its electronic navigational charts are fully updated and well maintained, IMO performance standards necessitate that a ship maintains backup measures. The arrangements necessary to satisfy the requirement that a ship can complete its journey without ECDIS include:

1. Prepared facilities to safely replace the functions of the ECDIS. This way, the ship will be able to safely continue its voyage in the event of an ECDIS failure.
2. A navigational replacement for the ECDIS in case of technical failure. A backup ECDIS is acceptable, as are paper navigational charts. Keeping both of these backup resources on hand is advisable but not necessary.

Maintenance of ECDIS Software

The second section of IMO Circular MSC.1/Circ.1503 deals with ECDIS software maintenance. Software maintenance is essential, as an ECDIS with outdated software may be unable to display recent charts correctly. Additionally, non-compliant software may be unable to trigger alarms, notifications, warnings, and other critical information present in the latest electronic navigation charts. In the worst case, an ECDIS without the proper software updates may even fail to install or load up-to-date charts.

The International Hydrographic Organization lays down the latest requirements for ECDIS software as part of the ENC Product Specification, as this page describes.

Operating Anomalies Identified Within ECDIS

The International Maritime Organization defines ECDIS anomalies as unintended or unexpected actions on part of an ECDIS unit. These anomalies may impact the function of the equipment, inputs from the user, and other elements of ECDIS function. While there are many possible anomalies that may occur, some examples include:

1. Alarm failures
   • ECDIS does not detect objects in the path of a voyage
   • Alarms do not activate when they should or activate when they should not
   • The system fails to manage multiple alarms correctly
2. Navigational feature failures
   • Incorrect display information which may result in misrepresentation of hazards
3. • Complex navigational lights appear incorrectly or not at all
   • Absence of lone hazards, underwater features, and detailed information

The user of the ECDIS should consult the equipment manufacturer in case of these or any other anomalies. Equipment failures of this sort underline the importance of maintaining a backup to the ECDIS.

The ECDIS Data Presentation and Performance Check that IHO has developed is a useful tool to check for proper function. Sailors, mariners, and other operators can use it to create artificial electronic navigation chart cells and run them through the ECDIS to test various elements of technical performance. This can provide for the advance recognition of potentially dangerous anomalies or confirm proper function before a voyage. The IHO website and major electronic chart providers offer this data set as well as guidance on using it properly.

ECDIS anomalies present serious risks to mariners, which is why the International Maritime Organization puts a priority on investigating and resolving them. Administrations may take several measures to help this process, such as encouraging vessels to report any anomalies that occur with their ECDIS equipment. Any report should come with details on the charts and equipment that involved the anomaly, which will make it easier to reproduce and fix the error. Additionally, governments and international organizations should share information with one another upon request. This will help to proactively warn any sailors who may be at risk due to an anomaly that another crew recently discovered.

Differences Between Raster Chart Display System and ECDIS

An operator can use their ECDIS in ECDIS mode or RCDS mode. While the former setting uses electronic navigational charts, the latter makes use of Raster navigational charts. Depending on the area where a ship operates, it may or may not have easy access to ENCs. Raster charts are, at their core, digitized paper charts. They lack the deeper technical functionality of modern digital charts and must be supplemented by relevant, up-to-date paper charts.

Stay Up to Date with American Nautical

While there are three more sections in IMO Circular MSC.1/Circ.1503, they don't describe best practices for operational use. Rather, they offer guidelines for training and initial ECDIS adoption. You can find and read the full document here. You can also keep up with the latest ECDIS information by following The Mariner's Blog. Find out more by exploring our website and seeing what we have to offer you.