Where to find it
From the map, tap on any vessel to open its details page
Tap the Current position tab
Scroll down to the Vessel position section
You will find the Data received from field indicating the source of the last AIS position
What are the different sources?
Source | What it means |
Terrestrial | The position was picked up by a land-based AIS receiver. Typically available for vessels near coastlines, in ports, or within range of a shore station |
Satellite | The position was captured by a satellite AIS receiver. Available for vessels navigating in open ocean or beyond the range of land-based stations |
Roaming | The position was received via a shared network of AIS receivers |
Why does the source matter?
Knowing the source helps you assess the coverage and freshness of the data:
Terrestrial positions are generally updated more frequently as vessels are within range of multiple shore stations
Satellite positions may have longer intervals between updates, particularly in remote ocean areas
If a vessel appears far offshore and is showing a terrestrial source, the position may be older than expected — always check the Data received on timestamp alongside
Satellite AIS and subscription
Viewing Satellite AIS position data requires a Mobile Pro Plan subscription. Without it, satellite-sourced positions may not be available for vessels operating beyond coastal coverage.