Garmin GPSMAP 8700 Black Box Owners Manual - Page 20
Viewing a List of AIS and MARPA Threats
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Heading and Projected Course of Activated AIS Targets When heading and course over ground information are provided by an activated AIS target, the heading of the target appears on a chart as a solid line attached to the AIS target symbol. A heading line does not appear on a 3D chart view. The projected course of an activated AIS target appears as a dashed line on a chart or a 3D chart view. The length of the projected course line is based on the value of the projected heading setting. If an activated AIS target is not transmitting speed information, or if the vessel is not moving, a projected course line does not appear. Changes in the speed, course over ground, or rate of turn information transmitted by the vessel can impact the calculation of the projected course line. When course over ground, heading, and rate of turn information are provided by an activated AIS target, the projected course of the target is calculated based on the course over ground and the rate of turn information. The direction in which the target is turning, which is also based on the rate of turn information, is indicated by the direction of the barb at the end of the heading line. The length of the barb does not change. When course over ground and heading information are provided by an activated AIS target, but rate of turn information is not provided, the projected course of the target is calculated based on the course over ground information. Activating a Target for an AIS Vessel 1 From a chart or a 3D chart view, select an AIS vessel. 2 Select AIS Vessel > Activate Target. Viewing Information about a Targeted AIS Vessel You can view the AIS signal status, MMSI, GPS speed, GPS heading, and other information that is reported about a targeted AIS vessel. 1 From a chart or a 3D chart view, select an AIS vessel. 2 Select AIS Vessel. Deactivating a Target for an AIS Vessel 1 From a chart or a 3D chart view, select an AIS vessel. 2 Select AIS Vessel > Deactivate. Viewing a List of AIS and MARPA Threats 1 From a chart, select Menu > Layers > Other Vessels > List > Show. 2 Select the type of threats to include in the list. Setting the Safe-Zone Collision Alarm Before you can set a collision alarm, you must have a compatible chartplotter connected to an AIS device or radar. The safe-zone collision alarm is used only with AIS and MARPA. MARPA functionality works with radar. The safe zone is used for collision avoidance and can be customized. 1 Select Settings > Alarms > Collision Alarm > On. A message banner appears and an alarm sounds when a MARPA-tagged object or an AIS-activated vessel enters the safe-zone area around your boat. The object is also labeled as dangerous on the screen. When the alarm is off, the message banner and audible alarm are disabled, but the object is still labeled as dangerous on the screen. 2 Select Range, and select a distance for the safe-zone radius around your vessel. 3 Select Time To, and select a time at which the alarm will sound if a target is determined to intersect the safe zone. For example, to be notified of a pending intersection 10 minutes before it will likely occur, set Time To to 10, and the alarm will sound 10 minutes before the vessel intersects the safe zone. 4 Select MARPA Alarm, and select an option for when the alarm sounds for MARPA-tagged objects. AIS Aids to Navigation An AIS aid to navigation (ATON) is any kind of navigational aid that is transmitted over the AIS radio. ATONs are displayed on the charts and have identifying information, such as position and type. There are three main kinds of AIS ATONs. Real ATONs physically exist and send their identifying and location information from their actual location. Synthetic ATONs physically exist, and their identifying and location information is sent from another location. Virtual ATONs do not actually exist, and their identifying and location information is sent from another location. You can view AIS ATONs on the chart when the chartplotter is connected to a compatible AIS radio. To show AIS ATONs, from a chart, select Menu > Layers > Chart > Navaid > ATONs. You can view more information about an ATON if you select the ATON on the chart. Symbol Meaning Real or synthetic ATON Real or synthetic ATON: Topmark North Real or synthetic ATON: Topmark South Real or synthetic ATON: Topmark East Real or synthetic ATON: Topmark West Real or synthetic ATON: Topmark Special Real or synthetic ATON: Topmark Safe Real or synthetic ATON: Topmark Danger Virtual ATON Virtual ATON: Topmark North Virtual ATON: Topmark South Virtual ATON: Topmark East Virtual ATON: Topmark West Virtual ATON: Topmark Special Virtual ATON: Topmark Safe Virtual ATON: Topmark Danger AIS Distress Signals Self-contained AIS distress signal devices transmit emergency position reports when activated. The chartplotter can receive signals from Search and Rescue Transmitters (SART), Emergency Position Indicating Radio Beacons (EPIRB), and other man overboard signals. Distress signal transmissions are different than standard AIS transmissions, so they appear differently on the chartplotter. Instead of tracking a distress signal transmission for collision avoidance, you track a distress signal transmission to locate and assist a vessel or person. Navigating to a Distress Signal Transmission When you receive a distress signal transmission, a distress signal alarm appears. Select Review > Go To to begin navigation to the transmission. 12 Charts and 3D Chart Views
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