ECDIS – the high-tech substitute of the paper charts


ECDIS stands for Electronic Chart Display and Information System. It is an electronic system providing navigational and safety information to the mariners and assisting them in route planning and monitoring. In short it is a very advanced substitute of the paper charts which were used for centuries.

The ECDIS displays navigational information from a System Electronic Navigational Chart(SENC) and takes as a minimum position, speed and heading information from external sensors. It could receive information from another sensors like Radar, Navtex, Automatic Identification System (AIS), depth sounders and others to provide more useful information to the navigator..

Electronic charts

The electronic charts are the foundation of the ECDIS system. There are two categories of charts – raster and vector. Both of them can be used by the ECDIS.

Raster charts

The raster chart is nothing more than a digital version of a paper chart. The paper chart is scanned and the result is an image called a raster chart. If you zoom out and especially zoom in the text and the symbols could become blurred, magnified and distorted. That can compromise the safety of the vessel. The raster charts are very easy to be produced as they are just scanned versions of the paper charts.  However if you use such charts you will can’t experience the full range of benefits of the ECDIS.  You will need to use paper charts as a back-up as well. We will come back to the legal requirements later.

Vector charts

These are created by the digital capture of individual charted objects and their attributes based on geographical positions. These objects are then stored in object oriented layers and database. The mariners can choose which layers to use according to the external circumstances and their own preferences.

A vector chart which fulfils the specifications known as S-57 is called Electronic Navigational Chart (ENC). The standard is created by the International Hydrographic Office (IHO) and can be found here. Only approved ECDIS supplied with ENCs complies with the SOLAS requirements.

The ENC will be transformed to System Electronic Navigational Chart (SENC) inside the ECDIS. The original ENC will be kept untouched and can be used to reconstruct your SENC in case it is damaged or destroyed. It is the SENC that contains updates to ENC and other data inserted by the operator. The SENC is an advanced version of a paper chart. It contains everything which is in an up-to-date paper chart but has also additional data such as sailing directions, tidal and lights information, etc.

In the recent years the only disadvantage of the ENCs was their limited coverage of the seas. Presently that issue is almost solved and the coverage is world-wide with small exceptions. The quality of the ENC is not the same in different regions. It depends on factors like:

  • Date and accuracy of survey. Some surveys are more than a century old.
  • The coverage and completeness of the survey may be doubtful. That depends on the authority which performed the survey and the invested resources.

The navigational data used by ECDIS must be the latest information produced by the authorized hydrographic office and in accordance with the IHO standards. Regulation V/27 of SOLAS requires all ships to carry adequate and up to date charts, sailing directions, list of lights, notices to mariners, tide tables and all other publications necessary for the intended voyage. ECDIS falls within the framework of charts and must also fully comply with these requirements.

ECDIS Updating

The updated data is very important during the preparation and monitoring of a voyage or otherwise the vessel’s safety could be compromised.  I need to remind you once again that the updates are applied to the SENC and the original ENC must be kept in its original form.

The updates could be separated on automatic, semi-automatic and manual.

  • Automatic updates. The fully automatic process means that the ECDIS is connected through an appropriate interface to a telecommunication system. That option is very easy for the users but makes the system more vulnerable to computer viruses.
  • Semi-automatic updates. They are applied by CD or any other storage devices. The updates could be received by e-mail, direct internet connection or supplied when the vessel is in port.
  • The manual process makes it possible to add, remove, alter and mark objects or areas on the electronic chart. This can be necessary if a navigational warning is received before the official update. It could be used to mark fishing or seismic survey areas or any other useful information for the mariner.

It is possible to display the updates currently being used in order to review their contents and ascertain that they have been included in the SENC. ECDIS must keep a record of updates, including time of application. Updates are produced by National Hydrographic Services and are distributed by regional data centers.

Implementation of ECDIS

In 2009 the Maritime Safety Committee approved amendments to the SOLAS Chapter V Regulation 19.2. It requires vessels engaged on international voyages to be fitted with ECDIS according to the following table:


ECDIS implementation table


The above mentioned amendment allows the vessels to use ECDIS as an alternative to the traditional paper charts. To do so the equipment needs to meet certain standards explained in Resolution A817(19).

It is under ship owner’s discretion to decide if the vessel will use the paper charts together with ECDIS or will abandon them for good. You can also choose to leave the paper charts as a back-up option or to keep them as a primary one. Keeping them both will be costly. It will require additional expenses for new editions of charts and additional man-hours for chart correcting. From my experience the ECDIS is a far better tool than any paper chart. It also saves a lot of efforts to keep the paper charts updated. I believe in near future the ECDIS will improve even more and all mariners will prefer to use them. To do so they must pass appropriate training.

ECDIS training

All Bridge team officers should have appropriate training in the use of ECDIS. All of them must pass a 5 days ECDIS generic course in an authorized training centre and obtain a valid certificate. They need to have also an ECDIS specific course for the type of equipment they will work with. It can be held in a training centre like the main course or to be done as an on-board training. In both cases the mariners must be able to work well with their equipment and to use all of its functions and options for maximum performance.

As a conclusion:

Good equipment, database, training and procedures are necessary to ensure safe and efficient use of ECDIS.



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