As of DataHub Firmware 4.31 and Anchor Alert App 2.0, a new feature, AIS Alerts, has been released.
AIS Alerts create a security zone around your boat at anchor in two new ways:
Collision Zone - A radius around your vessel in meters, by default 5m. Any vessel entering this zone is assumed to be near to colliding with your vessel.
Warning Zone - A radius guard zone around your vessel in meters, by default 50m. AIS vessels moving slower than "Speed" (default 3Kts) will generate an alert when entering this zone if they are on a collision course with your vessel. Vessels travelling faster than this will be assumed to be under active steering and not a risk.
What is required to use AIS Alerts
To use AIS Alerts in the Anchor App with the DataHub you need:
The Anchor Alert App version 2.0 or later.
DataHub Firmware 4.31 or later.
Anchor Alert App Pro subscription, or PredictWind Professional.
A VHF AIS receiver/transceiver connected to your boat's N2K network.
The DataHub connected to your boat's N2K network.
How to enable AIS Alerts
To enable AIS Alerts for the Anchor Alert App:
Log in to the DataHub on 10.10.10.1.
Click Services > NMEA > AIS Alerts tab.
Tick to Enable.
Add your boat's MMSI. This step is essential to avoid false alarms from your boat.
Click SAVE & APPLY.
Open the Anchor Alert App and tap Alerts > AIS Alert.
Enable the AIS Alert and tap the back arrow (top left) of the screen.
AIS Alert Configuration Options
AIS Alerts for the Anchor Alert App can be configured in the DataHub. Configuration options are:
MMSI - Add your vessel MMSI to avoid false alarms from your own AIS system.
Speed - Speed cutoff of approaching vessel in knots. Vessels travelling at this speed or faster will not generate an alert when they enter the warning zone unless they are on a course that will place them inside the collision zone.
Warning Zone - Radius of guard zone around vessel in meters. AIS vessels moving slower than "Speed" will generate an alert when entering this zone if they are on a collision course with your vessel.
Collision Zone - Radius of circle defining the collision zone in meters. Any vessel entering this zone is assumed to be at immediate risk of colliding with your vessel.
Frequently Asked Questions
What Settings should I use for Anchor Alert AIS Alerts?
For most users, the default settings of Speed 3Kts, Warning Zone 50m and Collision Zone of 5m should be suitable; however, this may vary significantly depending on your vessel size (length) and how crowded the anchorage is.
You may need to amend these settings at anchor before starting a new anchor alert session to ensure they are correct for your situation.
Does my VHF AIS need to be powered on for AIS Alerts to work?
Yes. Your VHF AIS needs to be powered on for AIS Alerts to work.
Though you may also have Over the Horizon AIS (OHA) enabled for your boat, targets received this way are not suitable for use with AIS Alerts because the Target Age (lag time from report to receipt) is in minutes, whereas VHF is real-time.
To be meaningful, AIS Alerts must be immediate.
When will AIS Alerts protect my boat?
AIS Alerts will work when your VHF AIS is powered on, and the Anchor Alert App is actively monitoring your anchorage.
To be detected by AIS Alerts for monitoring, the other vessel must have a VHF AIS unit which is powered on. If the other vessel has no AIS or is powered off, AIS Alerts cannot see it and monitor its position.
AIS Alerts will work on your iPhone/iPad while aboard if your boat is connected to either DataHub or boat Wi-Fi, and the Anchor Alert App is running in the foreground or background. To receive AIS Alerts remotely, your DataHub must be connected to the internet and your iPhone/iPad must have an internet connection.