I would like to obtain gis data of cargo, container vessels as well as small cargo inter-islands ships and for an educational non commercial project/publication on food trade across the Caribbean Sea. Any information available.
You could use AIS data.
I'm not sure for the coverage of the caribbean sea and the temporal extent. IMO it is difficult to get historical data for free, but for a start you could work with AIS data from NOAA (..into the blue: Puerto Rico and Panama Channel). For the caribbean sea you will have a poor station AIS infastructure (in logging terms).
Commercial sites like vesselfinder.com, vesseltracker.com and marintraffic.com offer also historical databases and show more stations.
To mine the cargo (drought) and ship type info's you could parse/read AIS Message 1 and 5. In Message 5 you will find DST (Destination) and ETA (Estimated Time of arrival). The are several AIS decoder available in the web. Kurt Schwehr has a good repository at github.