Shipboard Automatic Identification System Displays: Meeting the Needs of Mariners -- Special Report 273 (2003)

Despite the fact that carriage requirements for automatic identification systems (AIS) are recent, there is significant experience relevant to the display of AIS data aboard ship. The committee reviewed this experience by investigating a number of AIS operational testing programs and pilot projects in the United States and abroad to better understand requirements for AIS displays. The programs investigated generally fit into two categories: those evaluating or using systems that meet the ITU-R M.1371-1 standard for AIS (ITU 2001), the International Maritime Organization (IMO) universal AIS standard (referred to as 1371 standard AIS) (IMO 2002); and non-1371 standard AIS (referred to as “transponder systems”). Only the 1371 standard is applicable to the committee’s work, but few operational tests of the universal AIS are extant. The committee therefore reviewed operational experiences and tests of both 1371 and non-1371 standard AIS programs and projects in its work.

None of the trials and projects examined were rigorously structured to permit evaluation of data and display needs. Therefore, much of the information in this chapter is anecdotal, and preferences expressed may be local rather than global. The limitations of taking user preferences into account in developing display designs without careful evaluation must be recognized because incorporation of user preferences may or may not translate into enhanced user performance.

The committee investigated a number of existing applications and benefited from the experience of three of its members in the development and use of such systems in the lower Mississippi River, Tampa Bay, and San Francisco. In examining current projects, the minutiae of display technology were avoided, and the focus was on broader lessons that might apply. Although they were outside the committee’s charter, the experiences with symbology, display colors, arrangements of controls, and so forth may well become germane and can be applied at the proper stage of the display design process.

Perhaps the single most important lesson learned from examination of existing applications is that the technology is gaining acceptance by mariners, with commonality developing concerning both the basic information that should be presented and the form it should take. As mariners become accustomed to the technology and to the benefits of accurate, real-time navigational data, skepticism appears to diminish rapidly. In the lower Mississippi, for example, local mariners now recognize AIS technology as a tool that vastly improves the quality of navigational information available to them, simplifying the retrieval of that information in the process.

One of the most frequently cited issues is information overload. Mariners are concerned about the sheer volume of data becoming available to them, and the problems of extracting from that data in a timely manner the information needed in a form directly applicable to decision making. This suggests the introduction of filtering technology, the imposition of limits on the data flow from the vessel, or a combination of the two.

The operational tests and pilot projects underscore the need for clear indicators of when systems are functioning properly so that mariners recognize and understand the inherent limitations in both the data and the systems generating and displaying them. This touches on two critical factors: education and standardization. Both of these areas require considerable research, particularly in evaluating the degree to which AIS-related skills need to be incorporated into the provisions of the Standards for Training, Certification, and Watchkeeping. While standardization is actively being pursued with respect to the display of navigational information, an effort to standardize the details of the information itself may become necessary as an adjunct to the vast increases in data flow made possible by AIS.

Although it is still in progress, the European initiative to develop a “river information system,” which will enhance the effectiveness of inland waterway transportation, may offer significant information about the use of AIS for vessel traffic management and the safety of navigation. As envisioned by the project, AIS is an essential element in an information system designed to maximize the effectiveness of water transport with the goal, among others, of limiting the rate of growth of cargo transport by road. Under sponsorship of the European Union, the river information system intends to apply AIS both autonomously for vessel safety and in combination with shore-based facilities for lock queuing and regulating passage of waterway restrictions.

The project is well documented, and it is expected that the results of operational testing will be similarly available.¹

The case studies from which the information in this section was drawn are shown in Table 3-1. Both ITU-compliant 1371 standard AIS programs and non-1371 standard transponder programs were reviewed. Each project is discussed in the following sections, and key results are provided, if available.

In 2001, the St. Lawrence Seaway implemented an AIS project integrated with the seaway’s traffic management system. A team that includes the U.S. Saint Lawrence Seaway Development Corporation, the Canadian St. Lawrence Seaway Management Corporation, and marine transportation

interests is conducting this ongoing project, which was formally inaugurated on September 5, 2002. The AIS was developed by the U.S. Volpe National Transportation Systems Center and reached initial operational capability in July 2002. The necessary shoreside communications stations were installed, signal coverage areas were determined, and transmission frequencies were obtained. AIS transponders will be mandatory on all commercial vessels transiting through the seaway traffic sectors from St. Lambert (Montreal) to mid–Lake Erie beginning with the seaway opening on March 25, 2003, in advance of the IMO International Convention for the Safety of Life at Sea (SOLAS) schedule (Great Lakes St. Lawrence Seaway System 2001).

Through agreements with the Canadian Shipowners Association and the Shipping Federation of Canada, the cost of implementing AIS is being shared equally by commercial carrier users and the two seaway management corporations, Canadian and American. Shipowners will contribute $0.06 Cdn per gross registered tonne, applied to transits of the four segments of the seaway—upbound Montreal/Lake Ontario section, downbound Montreal/ Lake Ontario section, upbound Welland Canal, and downbound Welland Canal. All ships have been required to pay this levy beginning May 1, 2001. The maximum annual contribution per ship is $5,000 Cdn (Great Lakes St. Lawrence Seaway System 2001).

Final testing and initial operational capability of the AIS were completed in July 2002. Two evaluations of the St. Lawrence Seaway AIS project are currently scheduled—one a comparison of AIS use and electronic chart display and information system (ECDIS) use on the seaway and the other a study of the technical, organizational, and safety impact of AIS implementation on the seaway. Both studies began in July 2002 and involved nine Great Lakes vessels from four participating shipping companies and four AIS manufacturers—Japan Radio Company, Ltd., Marine Data Systems, Saab TransponderTech AB/ICAN, Ltd., and Transas USA. Nine fixed AIS units were installed aboard participating vessels, and two portable AIS units for deep-sea vessels transiting the seaway were procured in July 2002. Data gathering for both operational tests began in August 2002, and reports of the evaluations are scheduled in 2003 (St. Lawrence Seaway Development Corporation, personal communication, July 11, 2002).

Several countries in Europe have conducted operational tests of AIS, the most notable of which are Germany and Sweden. In 2002, the German

Waterways and Shipping Directorate in Kiel completed a series of conformity trials on 1371 AIS Class A and Class B units from a number of equipment suppliers. These tests were done to evaluate how well the equipment conformed to the specifications and requirements established by international standards and how the systems operated within the AIS environment in German coastal waters. However, the tests did not include any evaluation of shipboard displays beyond the minimum keyboard standard.

The German Federal Hydrographic and Maritime Agency in Hamburg is also in the process of conducting laboratory certification tests of Class A AIS shipboard equipment in preparation for issuing certificates for carriage on German-flag vessels, but again, no shipboard displays are involved in the tests. AIS equipment is installed on some vessels that regularly transit German coastal waters, however, and German shore-based vessel traffic control centers have experience with shore displays of AIS signals. Even though this work does not include shipboard displays, such shore-side experience may be useful to take into account. In addition, German researchers are investigating the feasibility and operability of integrating radar and AIS vessel-tracking information on one shipboard display. Research on how to best display this information is under way, with results expected in the near future. Appendix B summarizes information gathered from a visit by a small group of the committee to the German Waterways and Shipping Directorate in Kiel, Hamburg, Warnemunde, and the Kiel Canal.

The committee also received useful information from the Swedish Maritime Administration during its New Orleans Workshop (see Appendix A) and from a visit with Capt. Pettersson, Senior Nautical Advisor, on board coastal ferries in Sweden. About 150 of these passenger vessels in Sweden are fitted with AIS units, and most include shipboard displays. Operational tests of these systems have resulted in reports of beneficial use by Swedish mariners, but the reports are mostly anecdotal, with few analytical evaluations available for use to help determine design requirements.

Mariners involved in Swedish tests have preferences with regard to the type of data presented and the format in which they are presented (Pettersson 2002). For example, the preference for electronic charts over alphanumeric displays is almost universal. Also, most mariners want an accurate heading sensor on AIS displays because heading is quite possibly the most important part of a navigational message. Most also agree that heading needs to be sent at a high update rate and is more useful than rudder angle information, which can be misleading or ambiguous. These views have been expressed by

many who have witnessed the test operations and could be used in the future to provide expert input to design requirements.

In 1998, the Panama Canal began an AIS project designed to evaluate the utility of AIS information to traffic controllers and shipboard personnel transiting the canal. The AIS units were developed by the U.S. Volpe National Transportation Systems Center. Two hundred sixty Panama Canal pilots and many vessels participated in the AIS evaluation project. The Panama Canal authority made available portable AIS units for vessels, because there was no carriage requirement for AIS in effect at the time of the test. As a result of the evaluation, which began in October 1998, the Panama Canal authority will mandate carriage of AIS units for passage through the canal coincident with the IMO SOLAS carriage requirement schedule. Permanent installation of an AIS unit will be required, as will a three-prong, 20-volt AC pilot plug, which is mandated to be installed at the primary pilot station for use by pilots with carry-aboard AIS (St. Lawrence Seaway Development Corporation, personal communication, July 11, 2002).

The Canadian Coast Guard and three Princess Cruises’ ships participated in a non-1371 standard AIS evaluation project that was partially funded by the Western Marine Community’s Pacific Coast Marine Review Panel in the summers of 1999 and 2000. The objective of the project was to gain operational experience with AIS and to formulate recommendations on ways to integrate AIS into bridge team operations in British Columbian waters.² The transponders used in the test were made by Meteor Communications Corporation of Kent, Washington; the transponders sent out updates every 30 seconds. All observations were of ship-to-ship communications.

Despite interference from cliffs 200 or more meters high in Seymour Narrows that impeded radar detection, initial AIS position updates were being received more than 1 hour before rendezvous at a range of 30 to 40 nautical

miles. All participants were receiving updates at a regular 30-second interval about 30 minutes before rendezvous at a range of 14 to 16 nautical miles.

Bridge teams in the summer 1999 tests expressed a preference for receiving reliable AIS updates about 30 minutes before time of closest point of approach (TCPA), irrespective of the speed of the target. Although there was no consensus as to how to label AIS targets in these trials, all bridge teams agreed that the labels should be short to minimize on-screen clutter. One of the bridge teams preferred to use some of the ECDIS screen to show an AIS target’s rate of turn, if available, followed by P or S (port or starboard), particularly for targets with TCPAs of less than 10 minutes. Most bridge teams, however, preferred to avoid this clutter. The option to curve the course over ground (COG)/speed over ground (SOG) vectors emanating from an AIS target to reflect its rate of turn was rejected by project participants mostly because bridge teams felt uncomfortable with curved vectors.

Bridge teams in the British Columbia project also believed that AIS information superimposed on an ECDIS being used for route planning would provide information that was too unreliable to be worth cluttering the ECDIS screen. To reduce clutter on an active ECDIS screen, bridge teams preferred three levels of information about AIS targets:

• On a normal active working ECDIS screen: An AIS target icon includes position, course, and speed vector. For target tracking and to assist with contacting vessels by VHF radio, AIS targets were labeled with their call signs or a short abbreviation of their name in small print.

• Target highlights: By clicking on the label of a target on the active ECDIS screen, a small new window was opened, preferably on a part of the ECDIS screen not being used by the active chart, with the course, speed, range, bearing, CPA, TCPA, rate of turn, ship type, overall length, and full name, as well as a “more” button.

• Target particulars: Clicking on the “more” button provided target highlight information including voyage data such as destination, estimated time of arrival (ETA), draft, hazardous cargo information, unusual maneuvering limitations, towed barge information, and so forth, and the vessel’s own particulars.

Bridge teams in the British Columbia project thought it would not be appropriate to dead reckon an AIS target to place it on the screen in its

most likely position for more than just a few seconds from its last reported position, COG, SOG, and rate of turn. In addition, to reduce screen clutter, bridge teams preferred that automatic radar plotting aid (ARPA) A, ARPA B, and AIS icons of the same target be consolidated into a single icon. To avoid operator error, rule-based automatic consolidation was generally preferred over manual selection of icons to be consolidated.

Finally, intership electronic mail was tested in summer 1999. Mariners could pick from a list of short, traffic situation–oriented messages (“intend to pass you port-to-port”) that appeared in a window as soon as an AIS target was selected with a mouse click. Messages were preformatted and did not require keyboard entry to select or send. Messages were sent to AIS target ships as soon as one of the messages was selected and the selection confirmed.

Blinking circles around the icon of the e-mail sender were used to indicate arrival of an incoming traffic message from an AIS target. Clicking within this circle sent a confirmation of receipt to the sender and opened both the message and the pick list of standard replies (“OK”). Standard replies appeared on a pick list depending on the nature of the original message. Replies referenced the original message. Standard messages were used in this test of intership e-mail, and replies were not customizable so as to avoid “chat.”

Bridge teams in the summer 1999 British Columbia project believed that intership e-mail might reduce the need for intership and ship-to-VTS reporting VHF communications. However, bridge teams unanimously believed that the use of e-mail messaging could not be allowed to distract the officer of the watch (OOW) from accomplishing required tasks. Bridge teams also noted that adding another task to the duties of an already-busy OOW was undesirable.

Bridge teams believed that it would be useful to display new hazards, out-of-place buoys, and demarcation of traffic separation zones on screen. These “stationary icons” were recommended to be of a different type and to be identified as such on the ECDIS screen. Bridge teams also believed that AIS should be used to provide them with real-time visibility and wind data as well as currents observed at surface in critical passes. Bridge watch teams believed that ECDIS should show a special type of icon where actual realtime conditions are available.

In follow-up tests in summer 2000, participants in the British Columbia project made the following recommendations concerning AIS displays:

• To minimize clutter on an active screen, unselected targets, be they radar or AIS, should not be labeled and should not have a vector emanating from them.

• Unselected radar targets should be represented by the echo of the target, as should consolidated ARPA/AIS targets for boats smaller than 20 meters in overall length that have a TCPA of more than 5 minutes. The OOW should be able to select whether the latter should be displayed as an echo or as a diamond.

• Targets to be monitored for collision avoidance purposes should be selectable individually and by setting a guard zone. Selected AIS and consolidated targets should be displayed in the same fashion as unselected targets. Again, depending on the preferences of the OOW, icons for targets representing boats smaller than 20 meters in overall length that have TCPA of more than 5 minutes should be suppressed.

• The predicted path over ground should be displayed for selected targets. A maximum of 10 characters should be used to label each target. The label should default to the first 10 characters of the full name but should be editable.

• Collision avoidance forms, target information forms, own ship collision avoidance forms, and own ship information forms, with required information types, were defined and recommended by test participants.

• Test participants developed traffic control display recommendations.

• Display preference profiles were recommended that would allow individual users to set and edit their own display preferences in a profile document.

• SOLAS ships should have a fail-over capability, meaning that dual transponders should be carried and operational. If the primary transponder were not performing properly, an alarm should be sounded automatically on the bridge and a switchover accomplished to the backup transponder.³

In general, bridge teams in both the 1999 and 2000 British Columbia AIS project were pleased with AIS performance. Bridge teams noted differences in range and bearing between AIS and ARPA targets of the same ship, which reinforces the need for consolidation and avoidance of screen clutter. AIS “really shone,” however, when it came to filling in the many radar blind spots in Alaskan and British Columbian waters (Pot 2000).

The U.S. Coast Guard (USCG), in cooperation with local mariner organizations and pilots, sponsored a project on the lower Mississippi River to introduce AIS shipboard transponder systems into the maritime operations in the region beginning in 1998 and continuing through 2002. The project was part of an overall effort to upgrade and modernize vessel traffic systems on the lower Mississippi, and the operational experience with the shipboard units was used by USCG to help with the development of international standards for AIS. The shore-based component of this AIS was implemented by USCG through a task order with Lockheed-Martin in 1998. Also, in 1998, USCG issued a task order to Ross Engineering for the supply of 52 shipboard AIS transponders. USCG established formal agreements with local mariner and pilot organizations in the region to use these transponders and the AIS during their normal operations. The AIS operational test bed with this system was completed in mid-2002.⁴

Although no formal evaluation report is available concerning the lower Mississippi River tests of AIS, anecdotal information was collected by committee members through informal discussions with mariners who are familiar with the operations. Impressions and views from those discussions are presented in this section.

When AIS was first introduced in the lower Mississippi, it was met with skepticism among local mariners, who were concerned that the new technology would only add a level of complexity to an already complex system. However, as mariners became accustomed to the technology and the benefits of accurate, real-time navigational data, the skepticism diminished. For example, mariners recognize the value of AIS technology in improving the quality of navigational information and simplifying the retrieval of that infor-

mation because much information was automatically relayed to them. They also learned that AIS technology does not reduce the importance of such existing navigational tools as radio, ARPA, radar, and simply looking out the window.

Mariners on the Mississippi have noted that AIS technology improves bridge resource management and enhances safety and efficiency. For example, AIS can provide a real-time visual representation of the entire relevant waterway system, not just a particular vessel’s immediate vicinity, and this can enhance knowledge of traffic situations over a wide region as well as help with more efficient use of the waterway. As more vessels participate in the overall system, mariners foresee even more operational advantages.

In addition to praise for the benefits of AIS, mariners also voiced some concerns about the new technology. One is that of information overload, because with so much data readily available, mariners must learn how to recognize priority information without being distracted by peripheral “chatter.” They must know how to effectively use the data provided to enhance bridge resource management. They must know who should monitor what equipment and what information to relay to whom. It is also vital that mariners learn to recognize when the system is fully functional and when to verify data. For example, it was determined in this study that the AIS targets based on the Global Positioning System (GPS) are considerably more accurate than radar targets. The tendency, therefore, would be for mariners to rely heavily on AIS data to the exclusion of other sources. However, AIS data quality suffers when satellite contact is lost and the system switches into memory mode. The mariner might then be unknowingly relying on extrapolated rather than real-time positioning data.

Mississippi River mariners have noted that they must also be able to screen out information at various times, quickly and easily. For example, while AIS can generate a picture of the entire waterway system, mariners are generally more concerned with events and conditions in their immediate vicinity. They also need a way to filter out various alarms that do not require their immediate attention.

These mariners also voiced some concern about education and standardization. Since AIS data must be presented in a “common language” of symbols, colors, and sounds that is readily understood, all mariners who use the system must learn that common language, and education is necessary to

improve the skill level of all AIS users. Not only do mariners need commonality of available information, they also need instrumentation and data readouts that “speak a common language.” Information overload is only exacerbated if the information is presented in different ways at different times on different vessels.

Mariners trained on IMO-standard charts reported confusion when confronted with non-IMO chart products. There was almost universal agreement that colorization on electronic charts, AIS target and information symbology, and information retrieval procedures should be standardized according to guidelines established by IMO. Local pilots also suggested that pilot carry-ons use symbology and color codes that match a vessel’s onboard system.

Mississippi River mariners also expressed a preference for having all navigational equipment, including AIS, situated close together so that critical information is conveniently available. This is especially important in situations where the mariner must verify information from several redundant sources and for vessels carrying minimal keyboard displays. These alphanumeric displays are roughly the size of a shoebox and could easily be tucked in an obscure location, which would present difficulties for manual plotting and cause delays during critical times.

Mississippi River mariners generally agree that AIS should not be used to convey additional communications messages because that would overtax the system and distract the mariners from critical navigational alerts. They agree that text messaging in general would be most appropriately relegated to a separate, parallel system, operating concurrently with AIS but focusing on important nonnavigational data such as cargo and crew list. Regardless of the technology used, text messaging will require some kind of policing, perhaps with locally defined, allowable text messages.

The mariners involved in the lower Mississippi River AIS tests have concluded that several issues need to be addressed before the full value of the technology can be realized. For example, a common language of symbology, chart colorization, and alarms needs to be established, and existing electronic charts must be resurveyed to reflect accurate data. Radar accuracy in general needs to be improved. Equipment standards and procedures need to be established, and bridge personnel need formal training so that they can make use of all available tools.

While these results have neither been formalized nor compiled in a comprehensive evaluation report, they will be useful in informing future designs. However, considering the extensive AIS testing that has been done on the lower Mississippi River with a large segment of the mariner community, the committee believes that it would be appropriate to capture these observations in an overall evaluation and prepare a report on lessons learned.

The transponder-based pilot carry-aboard units incorporated into the Tampa Bay Vessel Traffic Information System (VTIS) provide another example of a display of AIS-type data tailored to the user’s needs that can be used to inform the development of future standards and guidelines. Tampa Bay is a large body of shoal water about 30 by 7 miles. The dredged main channel extends from the entrance over 40 miles to the Port of Tampa and varies in width from 400 to 700 feet. The channel is well marked, but navigational safety is frequently impaired when ranges and buoys are obscured by low visibility. Thunderstorms often occur, which generate high winds that affect ship handling and reduce visibility to near zero in heavy rain. In addition, rain can block most radar. The narrowness of the channel also requires planning of transits to avoid meetings in narrow reaches of the waterway.

In the 1980s the Tampa Bay Pilots Association considered using portable precision navigation equipment to assist navigation during low visibility. In 1995, the state of Florida established the Tampa Bay VTIS Consortium, and steps were taken to implement a concept with state-provided funding. The consortium worked with a manufacturer and developed pilot carry-aboard units, which combined electronic chart displays with transponder-based vessel positioning and identification. The system was intended to assist pilots with the navigational challenge presented by low visibility and with passage planning.

The carry-aboard unit consists of a VHF-FM transceiver, a Differential GPS (DGPS) receiver, a battery power pack with integral “universal” charger, an antenna, and a laptop PC. The antenna must be positioned on an external portion of the ship, free from interference. The charger will accept input from a variety of voltages, and the battery pack provides for about 6 hours of use.

The operator may select a series of different screens for display on the laptop, each conveying somewhat different information. An intermediate-scale display provides a general overview of the immediate area. One portion of the screen depicts the channel boundaries, and a pointer indicates the ship’s relationship to the channel centerline. There is also a digital readout of the distance left or right of the centerline. Other information displayed includes distance to the next significant navigational point, own ship’s course and speed over ground, geographic position in latitude and longitude, and data about the DGPS positioning used. Data about the closest other ship appears in a box in the lower right of the screen. Provision is also made for the transmission and display of data from the area’s Physical Oceanographic Real Time System, which is available from the National Oceanographic and Atmospheric Administration.

Experience and lessons learned from this program in Tampa Bay could provide valuable information for the development of future standards and designs of shipboard AIS displays.

In 1998, the state of California provided the San Francisco Marine Exchange with funds for a research project to develop new technologies to improve regional navigation and environmental safety. San Francisco Bay was selected as the test area because of its unique mix of navigational challenges such as varying weather patterns, high winds and fog, strong currents, and a moderately large tidal range. It has open water approaches, a relatively large bay, and many miles of narrow channels and rivers that require precision navigation and present diverse vessel traffic situations.

The project began by establishing a Joint Planning Partnership with representatives of ferryboat operators, tug companies, barge operators, container and tanker vessel operators, and the San Francisco Bar Pilots to oversee administration. Two committees were responsible for establishing the scope of work and project development and making periodic progress reports. The San Francisco AIS committee set up the criteria for acceptance of participants for the AIS evaluation. It identified a cross section of local port stakeholders and included those most active in both transits and geographic scope. Twenty-three vessels were designated to evaluate AIS in the following five areas of interest: vessel traffic management, vessel navigation safety,

reduced visibility/night navigation, bridge resource management, and overall vessel operations. Tug escort vessels, ship assist tugs, several high-speed ferries, a high-capacity passenger tour boat, a large commercial tanker, a large tug and tank barge, and an oil spill recovery vessel were included in the test.

The San Francisco committee’s primary focus was to evaluate the effectiveness of AIS as an aid in the practice of pilotage. Four units from different manufacturers were evaluated, and their individual strengths and weaknesses as a tool for the pilot were identified. Eight San Francisco Bar Pilots were designated to conduct the evaluations and submit their findings and recommendations.

Participants in the project concluded that the technology, although in its infancy, has the potential to develop into an effective navigational tool. “Universal AIS standards” were basic standards, or a starting point from which the AIS and linked technology could be developed on a regional or asneeded basis. Vessels at sea and vessels coasting have requirements different from those of vessels transiting port areas. Dissimilar vessel types and those in different services may also have particular requirements. The informational needs of pilots controlling large, deep-draft vessels in pilotage waters are different from those piloting other vessels and indeed may differ between pilotage districts. International, national, and regional regulatory agencies and other shoreside entities also may have requirements that could be met through the use of AIS and related technology. A concern of the mariner is the potential overload of the system with administrative information that could be transmitted by other means, which would negatively affect its use as a bridge information navigational tool.

The most common AIS features found useful by the San Francisco project evaluators were the following (in order of priority):

1. Radar target identification,

2. Position in traffic lane or narrow channel,

3. Vessel target information (i.e., speed and course),

4. Route planning,

5. Ability to make navigation decisions earlier,

6. Target destination, and

7. Ability to see around corners.

The San Francisco mariners involved in this project also had a number of common criticisms of the AIS they were using: the night screen was too bright, not all vessels were participating, there was screen clutter in areas of congestion, the system failed too often, and the navigation charts were poor.

A focus group of the AIS users was convened to discuss the usefulness of AIS and how it might affect the operation of their vessels or their particular area of interest. The group listed five goals for the development of AIS as a mature tool for the mariner and suggested topics to achieve each.

Selected members of the San Francisco Bar Pilots tested four portable pilot units, each manufactured by a different company. The evaluators were asked to appraise the units and AIS in the same interest areas as the AIS group (i.e., vessel traffic management, vessel navigation safety, reduced visibility/night navigation, bridge resource management, and overall vessel operations) and to submit the same evaluation report. A synthesis of the comments indicated that the units need further development before they become a reliable tool in which the San Francisco Bar Pilots can have complete confidence. The following are the minimum requirements that these evaluators thought necessary for portable pilot units in the future:

• The vessel’s true heading must be displayed.

• They must weigh less than 10 pounds.

• Electronic charts must be much more accurate to support the accurate positioning technology.

• The units must interface with the vessel AIS source information (position, course, speed) through a “universal plug.”

• The units should include a wireless Internet access to receive local meteorological, hydrological, and other notices of interest to the mariner.

• Nautical software developers should work with local mariners to incorporate features to meet their needs. Such features as route planning, continuous calculations of ETA at waypoints and selected locations, and position and time of meeting between selected vessels should be included.

The focus group unanimously agreed that continuing development of AIS and related technology should be strongly encouraged in the future. The results of this test and evaluation program provide many useful insights and can benefit the development of AIS display standards and guidelines.

A number of public and private organizations in the United States, Canada, and Europe have conducted operational tests and evaluations of AIS, many of which have included experience with shipboard displays. These tests were reviewed in order to understand how they might inform decisions about future requirements for displays aboard all types of vessels in U.S. waters. Most of the tests were part of research or pilot projects and used nonstandard versions of systems, usually known as “transponder systems.” Only a few of the tests used systems that met the IMO 1371 standard. Nevertheless, the results provide a general notion of how mariners have used shipboard displays and what benefits they might bring to a variety of operational and geographical situations.

In general, the tests did not use rigorous procedures to measure system performance on the basis of predetermined standards or requirements. Rather, the test results were mostly anecdotal; the comments by test participants reflected local views and applied to local conditions. Therefore, the tests are not suitable for analytical evaluation of display design performance,

but they do offer useful insights into mariner needs, preferences, and concerns about systems they have used in operational situations.

Mariners in a variety of U.S. port regions such as San Francisco, New Orleans, St. Lawrence Seaway, and Tampa Bay have gained considerable confidence from this recent experience as well as a degree of enthusiasm for the potential of AIS. Their initial skepticism diminished as they became accustomed to the technology and realized the benefits of accurate, real-time navigational data from AIS displays. In the lower Mississippi River tests of pilot carry-aboard AIS units, skepticism about the technology among local mariners diminished sharply after they became accustomed to the system and recognized the benefits that it offered. Similar results were noted among participants in the San Francisco Bay research project. The evaluation group from these tests strongly encouraged continuing development and noted the promise of future benefits. Across the Atlantic, extensive operational testing of shipboard AIS displays in Sweden resulted in enthusiastic support of further development within many international forums. These conclusions indicate that AIS can bring benefits that are recognized by mariners, especially when user needs are integrated into the design and development process.

The test results discussed in this chapter have also shown that designers must carefully consider such factors as reduction of information overload, effective integration of multiple bridge displays, training, and standardization. For example, information overload concerns were common among mariners who participated in test projects at all locations. The large volume of data that is typically available from multiple sources can be overwhelming, and all tests showed that excessive time is needed to extract pertinent information in a form applicable to decision making. This common problem supports the application of human factors principles by first considering the capabilities and needs of users and then designing and integrating all systems to meet those needs. Many of the test projects also showed that training and standardization are critical factors leading to successful outcomes. Both the Mississippi River and the Tampa Bay tests were used by USCG to help develop international standards for AIS.

To date, it appears that all AIS trials have been conducted in local areas by skilled operators with a common language and culture. Most have been done in pilotage waters where the operators are already familiar with the area

and traffic patterns. Thus, there is inadequate experience to predict how multilingual, multicultural crews with the lowest acceptable standards of training will react to AIS information.

The experience with all of the test projects, in general, shows that shipboard AIS displays can now enter the next phase of development with confidence that the technology can bring safety and operational benefits to mariners if it is properly designed and implemented. The projects also show that the next phase of development would benefit from more rigorous operational evaluations using lessons from these tests.

IMO International Maritime Organization

ITU International Telecommunication Union

Great Lakes St. Lawrence Seaway System. 2001. St. Lawrence Seaway AIS Project. www.greatlakes-seaway.com/en/navigation/ais_project.html.

IMO. 2002. IMO Resolution MSC.74(69), Annex 3. London.

ITU. 2001. Recommendation ITU-R M.1371-1: Technical Characteristics for a Universal Shipborne Automatic Identification System Using Time Division Multiple Access in the VHF Maritime Mobile Band. www.itu.int/rec/recommendation.asp?type=items&lang=e&parent=R-REC-M.1371-1-200108-I.

Pettersson, B. 2002. AIS: A Working System. Proc., Nautical Institute Workshop on Integrated Bridges. Nautical Institute, London, Nov. 13–14.

Pot, F. W. 2000. AIS Implementation: A News Round Up. Digital Ship, Nov., p. 26.