I like MarineTraffic for its very easy-to-interact-with user interface and the ease of extracting data from it. It provides accurate AIS data, and I find that compared to its competitors, it offers better partial details. Review collected by and hosted on G2.com.
It's a very costly tool. Ever since its Kepler acquisition, it hasn't been the friendliest to work on. Review collected by and hosted on G2.com.

