Electronic Chart Display and Information System (ECDIS) Practice Exam 2026 - Free ECDIS Practice Questions and Study Guide

In an Electronic Chart Display and Information System (ECDIS), the ownship symbol and its associated vectors are critical for accurately representing the vessel's position, heading, speed, and maneuvering information. To provide a comprehensive and reliable picture of the vessel's dynamics, at least three sensors are required to deliver data.

These sensors typically include a Global Navigation Satellite System (GNSS) for position data, a gyrocompass for heading information, and a speed log for speed over ground or through water. Each of these sensors contributes vital information that allows the ECDIS to calculate and display the ownship vector, ensuring safe navigation by depicting the current trajectory and speed of the vessel.

The combination of these three sensors offers redundancy and cross-verification of the data, which is essential to maintain the integrity of navigation operations. Therefore, having a minimum of three sensors ensures that the ECDIS can accurately represent the ownship's status and provide navigational aids effectively.