Sea route geometry is generated using searoute-py 1.6.0 (G. Halili, Apache-2.0), based on the Eurostat Searoute maritime network (EUPL-1.2), itself based on the Oak Ridge National Labs CTA Transportation Network Group Global Shipping Lane Network, World, 2000.
https://github.com/genthalili/searoute-py
https://github.com/eurostat/searoute
The modern connections and transport animation are illustrative and are not navigation data.