From "Eleytherios Venizelos" airport to the port of Piraeus :

From the airport of Athens you take the metro or the suburban railway and you reach the main port of Piraeus (station at the end of the green line-bottom left).

From the port of Piraeus :

From the port of Piraeus you will reach Poros:

A) Either by high-speed boat (flying dolphin) in only 60 minutes.
B) Either by boat in 2 hours and 15min.

Or by bus (KTEL) daily from the station of Peloponnisos (210-5124910-11-12) in 2 hours and 30 minutes through Korinthos and Epidavros.

In order to get informed about the departures from the port of Poros, please get in contact with FAMILY TOURS: (+30) 22980 - 23743, 22549, 26329.

Drive by Car :

If you have a car you can reach Athens in about 2 hours. 

Through the National Road Athens-Korinthos, we go left, after the isthmus of Corinth, to Epidavros.

After 30 minutes driving you reach the crossway to Epidavros; You must have seen the finger post for Poros or Spetses. Turn right to the crossway and turn left under the bridge. 

You follow the road, looking out for any finger posts for Poros. If you see any you turn left and reach the coastal road in 23 minutes to Galata, where you take the small ferry boat for Poros island.

Small ferry boats are scheduled for departure every 30 minutes and the ticket price is 4 € with the driver.

At Galata there is a big free parking for your car if you want to cross over to Poros island with boats in 5 minutes. 

If you want to cross over to Poros island with your car, within 5 minutes, you take the small ferry boats.