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Chapter 4: Security Regulations and Guidance 43 age vessel traffic movement. Non-surveilled systems consist of one or more reporting points at which ships are required to report their identity, course, speed, and other data to the monitoring authority. The U.S. Coast Guard authority to establish VTS with requirements for electronic devices was initially provided in the Ports and Waterways Safety Act of 1972 (PWSA), Title 33 USC 1221. The PWSA was a response to the collision of the tankers Arizona Standard and Ore- gon Standard under the Golden Gate Bridge in 1971, with the intent to establish good order and predictability on waterways by implementing fundamental management practices. Subsequently, the U.S. Coast Guard began to establish VTSs in critical congested ports, where ships must report their position, identity, and intentions to the vessel traffic center. A VHF-FM communications network forms the basis of a VTS, in which transiting vessels report to the vessel traffic center (VTC) by radiotelephone and are in turn provided with navigational safety information. In 1972, the first formal VTSs were established in San Francisco (California) and Puget Sound (Seattle). The VTS of Louisville, Kentucky, which is only activated during high water in the Ohio River (approximately 50 days per year), was started in 1973. Additional systems were established in Houston-Galveston (Texas), Prince William Sound (Alaska); Berwick Bay (Louisiana), and the St. Mary's River at Sault Ste Marie (Michigan). New Orleans and New York provided services on a voluntary basis throughout the 1970s and 1980s, but these operations were curtailed in 1988 because of budgetary restraints. In 1990, however, the Oil Pollution Act, a response to the Exxon Valdez oil spill, mandated participation in all existing and future VTSs. More information on each of the nine U.S. Coast Guarddesignated VTS areas can be obtained at http://www.navcen. Today, many VTS areas employ a variety of sensors and communications systems, including a network of radars and closed-circuit television cameras for surveillance and computer-assisted tracking. Many of the current technology AIS requirements discussed below began being phased into VTS areas during the 1990s. Each VTS publishes specific AIS requirements, with phased implementation plans. While not a specific criterion for VTS designation, the nine currently des- ignated VTS areas include all ferry systems with an annual ridership of 500,000 or more. 4.3.2 Automatic Identification System (AIS) An AIS is a shipboard broadcast system that allows vessel operators to more easily identify the position and heading of their vessel in relation to other vessels navigating in the area. It allows shore-based AIS stations to more easily monitor the location and heading of vessels in their area. The adoption of these systems is currently being phased in. An AIS includes a position-indicating transponder and an electronic charting or situation dis- play for accessing the information made available by the transponder system. It operates in the VHF maritime band and is capable of handling over 4,500 reports per minute and updates as often as every 2 seconds. When fully developed, AIS has the ability to provide a shipboard radar display with overlaid electronic chart data that include a mark for every significant ship within radio range, along with a velocity vector (indicating speed and heading). Each ship "mark" could reflect the actual size and GPS location of the ship. Classification, call sign, registration number, and other information could be displayed by "clicking" on a ship mark, ship name, course, and speed. Maneuvering information, closest point of approach (CPA), time to closest point of approach (TCPA), and other navigation information that is more accurate and timely than infor- mation available from an automatic radar plotting aid could also be available. Previously, this type of information has been available only to some VTS operations centers, but it will become available to every AIS-equipped ship. Shore-based AIS stations can provide text messages, time synchronization, meteorological and hydrological information, navigation information, and posi- tion of vessels.

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44 Part II: Characteristics of the U.S. Ferry System The AIS transponder normally works in an autonomous and continuous mode, regardless of whether it is operating in the open seas or coastal or inland areas. AIS stations continuously syn- chronize themselves to each other to avoid overlap of slot transmissions. The system coverage range is similar to other VHF applications, essentially depending on the height of the antenna. AIS's propagation is slightly better than that of radar because of the longer wavelength, so it is pos- sible to "see" around bends and behind islands if the land masses are not too high. A typical value to be expected at sea is nominally 20 nautical miles. With the help of repeater stations, the cover- age for both ship and VTS stations can be improved considerably. In the event of system overload, only vessels or ships farther away will be subject to drop-out in order to give preference to nearer vessels or ships that are a primary concern to ship operators. In practice, the capacity of the system is nearly unlimited, allowing for a great number of ships to be accommodated at the same time. The U.S. Coast Guard published a final rule in the October 22, 2003, Federal Register that har- monized the AIS mandates in SOLAS and the MTSA. AIS requirements of the MTSA are delin- eated in 33 CFR 162.46. Currently, AIS units are required for the following passenger vessels: All passenger vessels of 150 gross tons or more that are on international voyages as of July 1, 2003 (this requirement endorses SOLAS requirements for AIS) and All passenger vessels with capacities greater than 150 passengers and navigating in VTS zones designated in 33 FR 161.12 as of December 31, 2004. Thus, the Coast Guard is initially implementing AIS in VTS areas and for international voy- ages. However, areas and vessels required to have AIS units are expected to increases over time. NVIC 8-01 describes the certification process for AIS and other navigation equipment described under SOLAS. The Federal Communications Commission is currently developing rules for equipment authorization that, when finalized, will supersede NVIC 8-01. "Class A" AIS units meet International Maritime Organization (IMO) requirements for spe- cific broadcasts regarding position, navigation, and identification--both while underway and at anchor--to be able to both receive and transmit text messages. Vessels that must meet SOLAS requirements must have Class A equipment. Units that do not meet Class A requirements are able to broadcast position, course, and speed without the input of an external positioning device (e.g., differential global positioning system [DGPS]). Additional external devices (e.g., trans- mitting heading device, gyro, and rate-of-turn indicator) are recommended for vessels with these units, but are not required except as needed to meet SOLAS requirements for vessels in inter- national voyages. The International Electrotechnical Commission (IEC) has established a "Class B" certification standard. Class B units provide less extensive navigational information than a Class A unit, only receive (not transmit) text messages, and provide less vessel identification and descriptive infor- mation than a Class A unit provides.