MARINE VESSEL TRAFFIC
Presently Wolrd Commercial Fleet counts around 90,000 ships. Live Map of all types of ships you can see here.
If you know the name of the ship, its IMO, MMSI or ENI number you can track it in few seeconds.
Actually flight radars for ships are called live AIS Ships Trackers and look like this
By now the best ship tracking apps are MarineTraffic and VesselFinder.
Current location of a ship is easy to find with our search engine. Try it here.