By Bus to Kranidi or Ermioni
The KTEL bus service runs from the Athens station to either Kranidi (from which you can take a bus to Ermioni and catch a dolphin or take a taxi to Metoxi and catch the Freedom) or directly to Ermioni.
The bus routes and times are listed in English on the KTEL website. This is a fairly long trip and not as convenient as catching the hydrofoil from Pireaus, but it’s a handy option when boats aren’t running due to either weather or strikes. The buses are new and very comfortable and the mountain roads south of Corinth on the Peloponnese are scenic and often breath-taking, if at times a bit harrowing.