Locally probably-maybe even out of date-on shields, notes or perhaps screens. The train+BUS combo (pass valid on both, RES not even possible) runs at least ev hour, but I think starts from Ath proper and not Pireas. Your ferry will also not arr on exact time anyway. It is FAR more imptt to check form what quay the other ferry leaves from-if yuo have chosen the wrong one, it may mean a very long walk or expensive taxiride to that pier.
Generally in GR trains/bus stops fairly early and also starts next morning fairly early-the ride takes like 80-90 mins station to station. Google is also still quite helpful in giving links to these issues
Fur future reference: this timetable can be found on https://www.hellenictrain.gr/en
Currently bus to Kiato (run by Greek railways, included in the pass), then train to Athens.