- What it is
- An AIS-SART is a small AIS transmitter with its own GNSS (GPS) receiver. It sends its position as an AIS message, so the rescue ship sees it as a target on its AIS display, chart plotter, ECDIS or radar with AIS overlay.
- MMSI 970
- Its ID always starts with 970, then a 2-digit maker code and a 4-digit serial (for example 970 01 2345). 972 is an AIS man-overboard device, 974 an AIS-EPIRB.
- On the display
- A circle with a cross, and an alarm with the text SART ACTIVE. In a self-test it sends SART TEST instead.
- Frequencies
- The two AIS channels, 161.975 MHz (AIS 1) and 162.025 MHz (AIS 2), in the VHF band.
- How often
- Once a minute it sends a burst of 8 messages, 4 on each AIS channel, so the position keeps updating.
- Switching on
- Starts transmitting within about a minute. The GNSS light shows when it has a position fix.
- Range
- At least 5 nm from a ship, about 5–10 nm in practice with the SART about 1 m above the sea. Much further from an aircraft. Height matters: get it up on its pole.
- No radar needed
- Unlike a radar SART it does not wait to be triggered: it transmits by itself, and it gives an exact GNSS position instead of 12 dots.
- Battery
- At least 96 hours of operation. Replace by the expiry date on the label.
- Carriage
- Can be carried instead of a radar SART to meet the SOLAS SART requirement.
- Testing
- Use the TEST button, not the ON switch. Your own AIS should show SART TEST. Keep tests short.
- Switched on by mistake
- Switch it off straight away. Ships' AIS displays nearby will have shown a SART ACTIVE alarm.