The AIS table shows a list of the vessels, base stations, aids to navigation and search and rescue aircraft from which you have received AIS signals. It is updated every 10.5 seconds. The table is sorted to show the riskiest targets first. Potential 'close shaves' are shown in red at the top. These are targets that will come close to us within the next 30 minutes. Below these, in grey, are targets that have been detected but whose position is not yet determined—they could be close or they could be miles away. Finally, in black, are the remaining targets sorted in ascending order of their closest approach to us (if converging) or current range from us (if diverging). Select an item in the table to display certain details of the target, namely its last known range and bearing from you, whether the range is steady or diverging or, if you are converging, the closest point of approach, the time the target was last seen and its unique identification number (MMSI). Double click the item, or click 'Find' to scroll the chart to that target and view more details about it. Click ‘Detail’ to open the AIS Library and show full details and a history of sightings of the selected target.

In this example, we have simulated our own vessel (in red) sailing in Hong Kong's busy waters. An enormous cargo ship is leaving the container port. The yellow label (plus a sound alert) warns us of an imminent close shave. She is currently 0.66 miles from us but, if both she and we maintain our current course and speed, the closest approach will be a mere 39 metres in less than 3 minutes. The ship's confirmed track in the last 5 minutes is shown by the solid blue line (just visible behind the pink label) and her projected track in the next 5 minutes by the dashed grey line ahead of her. Our own track is shown in red with our projected track in dashed grey. Since the ship is massive and will no doubt want to stay in the fairway and the predicted closest approach is unacceptably tight, an immediate decision on whether to change course is clearly required. back