What is the quickest route from Italy to Athens via boat?

Try www.greekferries.gr

www.greekferries.gr

Bari, Brindisi and Venice are the three Italian ports where you can catch a ferry to Igoumenitsa and Patras, Greece. From Igoumenitsa and Patras you have to take a bus to Athens.

Depending on where you start out, it might be cheaper to take a cheap flight from Rome or Milan on Aegean Airlines.

http://www.aegeanair.com/aegeanen/home/index.asp

From Patras you can also take the train to Athens.

It's a pretty ride with the coast on one side and the mountains on the other.

The main Italian port for services to Greece is Ancona, but there are also services from Venezia, Bari and Brindisi. Your choice will depend partly on where you are in Italy. The three best operators are www.minoan.gr, www.superfast.com and www.anek.gr.