It does not support Cargo Ships.
There are specific changes to make, and while in principle you're right about the fact that they're not so different from trains, there is still be a non negligible amount of work to implement specific logic, make it work reliably, document it, etc.
Never tell a developer what's simple, they'll see for themselves ;)
However I fully support this feature request, LTN does support Cargo Ships for example. I'm tempted by a cargo ships-centric base but not having a powerful mod behind like Cybersyn would make it too much of a hassle.
I understand that could be low priority, though. Or even out of scope, then it could be an intermediary compatibility mod but that might make things much more complicated.
By the way if one really wants smart Cargo Ships now it is absolutely possible to run both Cybersyn and LTN at the same time.
