Passenger traffic was increased at the ports of Piraeus, Rafina and Lavrio on Fridat ahead of the August 15 national holiday, traditionally viewed as the peak of the Greek summer season.
Twenty-eight ferry services are planned from the port of Piraeus on Friday, 12 from Rafina and nine from Lavrio.
Port authorities urge passengers to be at the port one hour earlier to avoid delays.
On Thursday, 23 ships departed from the port of Piraeus with 19,743 passengers for various Aegean islands. Thirty-three ships with 4,931 passengers sailed for the Saronic Gulf, seven ships departed from the port of Rafina, and seven from Lavrio.