The preferred method of travel from Athens to Ermioni, if car is not available, is by sea from the port of [wiki=5ea66e4b85fa9287d6b204fdb8169c24]Piraeus[/wiki]. In high season several passenger-only hydrofoils and catamarans of [url=http://www.hellenicseaways.gr]]Hellenic Seaways[/url]] depart the port of Piraeus daily, calling at the the islands of Poros, Hydra and Spetses, as well as the mainland ports of Ermioni and Porto Heli on the Peloponnese. Depending on the ports of call, trip duration from [wiki=5ea66e4b85fa9287d6b204fdb8169c24]Piraeus[/wiki] to Ermioni is between 2 hours and 3 hours. Passenger tickets cost €29,5 one way.
Winter sees a major reduction in service, with only four hydrofoils daily. These are subject to cancellations when the weather turns nasty.
There are daily busses from [wiki=e14045c6b4fe1e65d04aade91b1f8c1b]Athens[/wiki] and [wiki=b48998c5d979d13343caf1b83e0cd74e]Nafplio[/wiki] to the nearby town Kranidi(approximately 9km from Ermioni). The ticket from Athens costs €15,30 one way. The trip takes longer than the car trip because the buss stops to a number of towns along the way. From Kranidi there are daily busses to Ermioni, however the departure times are rarely convenient to people arriving with the buss from [wiki=e14045c6b4fe1e65d04aade91b1f8c1b]Athens[/wiki]. Another way to reach Ermioni is to hire a local taxi but be sure to ask for the price beforehand, as well as a receipt. The cheapest way is, of course, hitch-hiking.
From [wiki=e14045c6b4fe1e65d04aade91b1f8c1b]Athens[/wiki] the trip is approximately 2 hours and 30 minutes.
From [wiki=b2031b8d0fcef9791975acf2f4bd0504]Nafplion[/wiki] the trip is approximately 1 hour and 15 minutes.