The Automatic Identification System (AIS) is a new international safety standard that aids collision avoidance for all sizes of vessel.
The fitting of an AIS transponder, which automatically transmits position, velocity and heading, is now mandatory for larger vessels.
The name of the ship and the VHF call sign are also usually transmitted.
Properly equipped with AIS your Chartplotter or PC Chart system will show vessels on your chart together with their headings so you can determine if avoiding action required.
AIS transmits an NMEA string compatible with most Chartplotters and Charting systems.