It is reported that "if there is a crowd, they may call out names instead" and that you should "be there by nine, or your ticket might be given away!" (http://thessaloniki.pbworks.com/w/page/22156781/Visiting-Athos) FoMA has had no direct report of this happening.
Because the office closes at 2:00 pm and opens at 8:00 am, persons planning to depart on the early morning ferry boat (departure time: 6:30 am) should arrive the day before their departure date in time to get their tickets before the ticket office closes.
It is worth buying a return ticket to ensure a place on the boat on the day you plan to leave Athos, in order to avoid the inconvenience of ticket lines and crush of crowds at the ticket office in Daphni while holding your luggage. Advance purchase of the return ticket is advisable if you intend to leave from one of the monasteries along the ferry boat route without returning to Daphni, although ferryboat tickets for the return to Ouranoupolis can also be purchased on the boat.
Header Image: Detail from a pilgrimage souvenir print produced for Philotheou Monastery in 1849. The detail depicts the arrival of the "pious pilgrims" on horseback, with the monastery on the left and two monks waiting to greet the arriving pilgrims.
Photograph by Robert W. Alllison, © 2011. The original print bears the following inscription (in Greek):
This bronzeplate print of the Holy Monastery of Philotheou on the Holy Mountain of Athos was printed at the personal expense of Nikolas Emmanouel Chionakes of Crete for the salvation of his soul and those of his parents and kin, and it was dedicated freely for pious pilgrims.
Printed in Moscow on 4 August, 1849. /div>
The Friends of Mount Athos
Dept. of Philosophy & Religion, Bates College
Lewiston, Maine 04240
http://www.athosfriends.org/travel_advisories/athoniki-office.shtml