The Gulf of Corinth or the Corinthian Gulf (Greek: Korinthiakόs Kόlpos) is a deep inlet of the Ionian Sea separating the Peloponnese from western mainland Greece. In medieval times, the gulf was known as the Gulf of Lepanto.
Shipping routes between the Greek commercial port Piraeus to western Mediterranean and hemisphere ports pass along this gulf. The dimensions of the Gulf of Corinth are approximately 105 km long and 30 km wide with a basement depth of 3 km at its center.
This is a passage route, rather than a cruising ground. If your cruise plan is to circumnavigate the Peloponnese (a rewarding six to eight week cruise, depending on your natural pace) it's best done anti-clockwise to use favorable winds for 75% of the journey. So carry on south.