The busiest time of the week for travel from Ermioni to Pireas by ferry is at 6:00 AM on Thursday. When planning to travel around this time, tickets should be booked well in advance as they may sell out. Around 7:00 PM on Sunday is when the fewest number of ferry tickets are sold. If you’re looking for a little extra space, the ferry departing at this time is the least likely to be crowded.