If you have the ships "callsign" usually 4 letters, you can go to this website:
Weather observations and positions of ships at sea
It is also possible to use the ship's name, but no info on the ship my car came over on showed up with just the name. I had to use the callsign for any info to come up.
When the ship makes a weather report the position is plotted, so you can track it's progress to Baltimore. The ship my car came over on seemed to make a report about every 12 - 18 hours.
Unfortunately I can't remember where I found the ship's callsign. There was a website mentioned in a "tracking" thread that listed all the cargo ships and when you selected one, there was all the info on the ship including the callsign.
Good luck!