For my research project, I need vessel traffic data of the most congested regions of the world for the past five years.
I searched for that data here but couldn't get what I wanted. So far I've found historical data for the US coast, the Australian seas and from the Indian government.
I've also looked at the vessel traffic services (marinetraffic, vt explorer, fleetmon....) but obviously they are commercial services, and even if they provide a free service, it is very limited where you can barely get the data of one vessel for a very limited time-span.
I also wonder if any of you did contact those commercial vessel traffic services, and request their historical data (for free) for a research project with no commercial intention. If so, how was their response?