Sea Essay is fitted with an AIS transponder. Her last recorded position can be viewed using a number of external websites.
Eg For example using vesselfinder.com. To see where Sea Essay has been in the previous 24 hours look for the following on the screen and
MarineTraffic.com provides a similar service with a ~3 day track history for free.
ShipAIS is an alternative service. It is also free to use and has a much longer archive / memory.
Please let me know if you are aware of other services. Especially any that display a longer historical record for free or which allow a data download.