If you have your own car or have rented one, then you can easily get from Athens to Ermioni, an area across from Hydra, in about 2 hours and 45 minutes.
Following the Attiki Odos and then the Athens - Corinth National Road, immediately after the Isthmus, go right to exit 10 (Corinth - Epidaurus) and immediately after turn left, under the bridge , on the road that leads to the Baths of Fair Helen and continues towards Epidaurus.
Drive for about 45 minutes and reach the junction for Epidaurus. A little before you will see signs to Poros or Spetses. At the intersection go right and immediately after turn left, under the bridge.
Continue on this road, meeting the "Vassilopoulos" supermarket on your right.
A little further down you will meet signs at another intersection , in which you continue straight on the road you were on, following the signs "towards Spetses and Hydra".
After about 40 minutes and just before you reach Kranidi, at another intersection you come across a sign pointing "to Ermioni", which you reach after a while.< /p>
The road is quite good and for the total route from Athens to Ermioni, at an average speed, we need about 2 hours & 30'.
Give us a call, so we can wait for you in Ermioni and take you from Ermioni to Hydra in a few minutes.