Nearby tracks can provide additional context to a Skylight event. The map tool () on the left side of Skylight allows you to view all vessel behavior within a limited, zoomed-in area.   

The intent of this feature is to help analyze the context of a specific event. For example: 

• See vessels in the vicinity of a Dark Rendezvous event
• Check whether there are AIS-transmitting buoys or equipment in use nearby
• Investigate whether an event occurred in a shipping lane
• Understand the activity of AIS transmitting vessels in a small, restricted area, like a Marine Protected Area

The intent of this feature is NOT to:  

• Analyze all vessel activities in a large region to answer more general questions, such as how many vessels are in the area, what type, what flag, etc. 
• Find a specific vessel and track it

Basic functions

View all tracks is only available when zoomed in. The icon has three colors indicating its available and status.

• Available - Click to turn on all tracks
• Enabled - Click to hide all tracks
• Not available - Zoom in to make available

To see the names of vessels from the tracks on the screen, click a small circle along the track to reveal more information about a vessel. 

Examples 

See vessels in the vicinity of a Dark Rendezvous event

Link to Event.

Check whether there are AIS-transmitting buoys or equipment use nearby

Investigate whether an Event occurred in a shipping lane

Link to Event.

See vessels in a restricted area

Link to Area and Timeframe.

Other notes

AIS in its raw form is a very messy data source. That messiness particularly surfaces in features like this.

For example, horizontal lines that are not realistic for vessel movement (e.g. cutting across land) is currently a common occurrence. This can be due to many reasons, such as corrupted AIS messages, issues with AIS receivers, or multiple vessels transmitting on the same MMSI number in different parts of the world. 

More about AIS positional points and tracks here.