Competence 4: Use of ECDIS to maintain the safety of navigation

This competence requires a thorough understanding of the capabilities and limitations of ECDIS operations. This includes knowledge of Electronic Navigational Chart (ENC) data, data accuracy, presentation rules, display options, and other chart data formats, as well as awareness of the dangers of over-reliance on ECDIS and familiarity with the required ECDIS functions and performance standards.

ECDIS uses ENC data, which is vector data produced to IHO S-57 standards. The accuracy of ENC data depends on the quality of the surveys used to create it. ECDIS has various display options to control the visibility of ENC objects based on their importance, such as the “Standard Display” and “All Other Information” settings. The system also has a SCAMIN attribute to reduce clutter by hiding certain objects when zoomed out beyond specified scales. ECDIS can integrate data from other sources like radar, AIS, and its own GPS position.

While ECDIS enables many useful capabilities, it’s crucial to understand its limitations and avoid over-reliance on it as the sole means of navigation. Inaccurate or outdated ENC data can lead to groundings and accidents, so it’s essential to keep ENCs updated to the latest edition. GPS input is subject to failures, interference, and spoofing, which can cause ECDIS to show incorrect positions if alternate positioning methods are not used. Incorrect safety depth and contour settings can give a false sense of safety, so these critical settings must be double-checked. Over-reliance and fixation on ECDIS can lead to a lack of visual lookout and situational awareness, so ECDIS should supplement lookout, not substitute it. System failures require effective backup arrangements, either a second ECDIS or paper charts, and the crew must be proficient with backup methods.

The IMO has specified required ECDIS functions and performance standards that a type-approved ECDIS must have, including route planning capabilities, route monitoring alarms, the ability to update ENC data, display of own ship’s position, heading, and speed, the ability to take electronic bearings and distances, automatic ENC loading and seamless display across ENC boundaries, display of important navigation-related information from ship’s sensors, and an adequate backup arrangement with a separate power supply. Specific performance standards are detailed in IMO Resolutions A.817(19), MSC.232(82), and IHO S-52.

Compared to traditional paper charts, ECDIS offers several advantages in terms of capabilities, workload reduction, and passage planning efficiency. ECDIS provides real-time positioning on the chart, improving situational awareness, and greatly reduces the workload of manual chart corrections. Voyage planning is faster and easier with ECDIS route planning tools. However, ECDIS also introduces new limitations and failure modes that navigators must thoroughly understand. A balance of proper ECDIS use and traditional navigation skills is optimal.

ECDIS significantly improves the efficiency of passage planning compared to paper charts. Route planning tools allow quick creation and editing of waypoints and routes, and passage planning is typically 50% faster with ECDIS. The system continuously monitors the ship’s position and planned route in real-time, providing automatic alarms for off-track limits, safety contours, and deviations from the plan. Electronic chart corrections are much easier to manage than manual corrections on paper charts. ECDIS also integrates data from various navigation sensors into one display, enhancing situational awareness and decision making. The accuracy of ECDIS allows more precise navigation and arrival planning.

Concluding, ECDIS is a powerful navigational tool that offers significant benefits over paper charts, but it comes with limitations that navigators must thoroughly understand. Proper training, procedures, and backup arrangements are essential to use ECDIS safely and effectively while maintaining traditional navigational skills and situational awareness.Sources:

Sources:
https://iho.int/iho_pubs/standard/S-66/S-66%20Edition%201.1.0_Final_Clean.pdf
https://www.nautinst.org/technical-resources/technical-library/ecdis.html
https://www.imo.org/en/OurWork/Safety/Pages/ElectronicCharts.aspx
https://www.marineinsight.com/marine-navigation/pros-and-cons-of-ecdis-or-paperless-navigation-of-ships/