[byproxy]

Ships & boats only make up 3% of transportation emissions in the United States: https://www.epa.gov/sites/production/files/2019-06/documents...

Does anyone have the numbers for other parts of the world?

[steve19]

That would measure only US transportation vessels between US ports, not imports or exports.

It would exclude Navy, Coastguard, fishing, pleasure vessels and I would assume cruise ships.

Sea transportion between ports is limited in the USA due to a law preventing non-US ships transporting between US ports.