Athens: We did Acropolis on our own. Then We did the Mycenae tour booked from the Electra palace hotel. We are going to do the Archeological museum on the last day before we leave for the ship. There was a teacher strike and the front desk warned us not to go.
Embarkation: We arrived the port around 12:30. The check in line was long but efficient. It took about 40 minutes and we were in our room. That 40 minutes includes the shopping time at the duty free shop.
Make sure you sent in the advance-registration 14 days prior departure. Otherwise, they sent you to another line to line up all over again. The couple at the next counter said they did send it in but they were sent to another line anyway.