Great site for AIS information
I found www.marinetraffic.com last week. This appears to be a worldwide AIS realtime site and was quite up to date, only about 2 minutes old. I checked this by looking at myself on the Red Funnel ferry to the Isle of Wight last week. The screen grab shows the Port of London vessel Yantlet heading home after surveying off Burnham-on-Crouch today.
