Electronic Chart Display Information Systems (ECDIS) and Automatic Radar Plotting Aids (ARPAs) are on nearly all U.S. Navy warships. Their use is governed by various International Maritime Organization (IMO) standards and Navy policy requirements. These systems give ships more data inputs and information display functions than the legacy capabilities of paper charts and nontracking radar video displays. In addition to ECDIS and ARPA, other electronic navigation and bridge management tools such as the Automatic Identification System (AIS), GPS, digital magnetic compasses, and direct messaging functions on bridge-to-bridge radios can be found on the bridge of any modern Navy ship.
These electronic systems greatly ease information processing and provide increased awareness for the ship control teams conducting navigation and contact management tasks. But these systems, with their complex and networked technology, can also present real dangers to their operators. Unwary users can suffer from data overload and an unsafe fixation on the electronic picture. Here are six simple rules to assist bridge watchstanders in using electronic systems more effectively and preventing bad habits.
Understand the system inputs. The prudent mariner will have a deep understanding of the electronic systems and not just blindly manipulate on-screen data. Operators should know what data is feeding the systems. This includes all the position, timing, and speed inputs for navigation; radar, video, and AIS inputs for contact management; and the environmental inputs affecting the ship’s movement. These various data feeds can come from separate systems, so understanding their networked interactions is important. Electronic systems can become unresponsive or provide false information if incorrectly used or improperly configured. Bridge team leaders need to ensure appropriate oversight and management of the “system of systems” underlying the electronic navigation tools.
Actively manage and process alarms. The prudent mariner will adjust alarm priorities as the ship moves from one navigation region to another (e.g., from coastal waters to harbor transits) and one contact situation to another (e.g., from open-ocean to narrow channel transit). The procedures governing alarm management—including IMO-required alarm notifications, Navy-required alarm settings, and the ship captain’s orders for alarm actions—are outlined in the system documentation. Personnel responsible for the setup and maintenance of electronic systems need to integrate alarm-setting checks into their actions. Operators need to be aware of the active alarms, what level of priority each should be given, and what those alarms indicate about the systems being used or the operational environment.
Set up an efficient display. The prudent mariner understands that excessive information clutters the screen and obscures needed data in a fast-paced decision-making process. Subject to the required settings from Navy or ship guidance, the goal of any system setup is to maximize the system’s effectiveness in complex environments. Common precautions include keeping the scale of a digital chart appropriate to the navigational area, setting a radar range appropriate to the approach of traffic, and using offset displays to maximize coverage, while not overlooking critical areas. Operators should avoid excessive reduction of display clutter to prevent critical information from being hidden. The screen setup should easily identify own ship, show nearby hazards, and prioritize contacts representing a risk of collision.
Know what is on the screen. The prudent mariner will never assume the information on the screen will remain the same from one look to the next. Electronic displays are subject to change, especially if other operators are using the same screens. One’s personal scan pattern should include a means of checking settings and system status prior to viewing the main content of the screen’s data. This scan pattern could include position source, water depth, heading, course over ground, vector type, and range scale. Once that initial check is complete, then users can develop electronic situational awareness.
Match electronic situational awareness to reality. The prudent mariner will constantly compare the information on the electronic screens with what can be seen outside the window. Looking out the window is as important in electronic navigation as it is when using just paper charts. The visual picture not only provides supplementary information to the watchstander, but also confirms or differs from electronic situational awareness. For example, the target angle of a contact on ARPA should match the actual view of the target out the window. Likewise, a nearby navigation aid’s ECDIS position should match its visual location relative to the ship.
Do not mix watchstation functions. The prudent mariner will have clear procedures in place to keep contact management functions on ARPA screens and navigation functions on ECDIS screens. ARPA and ECDIS have different purposes: The former assists with contact management and the latter with navigation. With many integrated electronic systems there is significant overlap in functionality, to the point where a skilled operator, with the right display setup, could navigate on an APRA system and manage contacts on an ECDIS screen. However, a screen meant for contact management will become adversely cluttered if all the navigation information is displayed, and vice versa. Though some level of data overlap is encouraged to promote situational awareness, operators should be wary of fully using one system for the other system’s tasks.
Finally, no two Navy bridges are the same. Between various system architectures, physical configurations, and, most important, local shipboard practices, any given bridge will always be slightly different from the rest. Whether a ship has the newest Integrated Bridge and Navigation System or only a legacy nonnetworked pilothouse, watchstanders should be intimately familiar with all the ship-control equipment installed and be ready to operate under any condition.
