I did some research when updating this mod: https://mods.factorio.com/mod/ships_extended trying to introduce sort of 'harbor' and automation, but faced several difficulties like unsupported alternate rail categories, complicated AI pathfinding apis...But glad to see your mod make such effort here! It's the first mod I've seen that makes shipping easy-to-use. AAI programmable vehicle is powerful, but it takes too much effort to program ship behaviors.

The original author of https://mods.factorio.com/mod/ships_extended made a nice ship model, and looks like it's fine to introduce his model with credits for its license.Can you add them into your mod as an alternate cargo ships?

BTW, entity name of cargo_ship_engine & curved water way is missed in current locale files.

Thanks for the feedback. maybe i'll use his model for a different type of ship? i'll check it out when i get the time work on this mod again.

https://mods.factorio.com/mod/ships_extended is on top version (0.16) but can't cross the line (water ways (rails)). Please can you think about this?