I have spent all morning trying to book a reservation for us in August, using our Global Interrail Pass, for a Blue Star Ferry crossing from Piraeus to Syros.
The Pass gives you a 30% reduction and this is indicated on the booking form, with the reduced ticked price. There is a box where you have to fill in your discount details and I give the pass numbers of our activated Global Pass. However, when I get to the point when I want the payment to go through, a box flashes up saying that “The document number is not valid”.
I tried this several times, then called the Greek number at the bottom of the page. The very helpful, English-speaking person who answered tried to book this passage for me, but lo and behold, the Global Pass number was indeed not valid. It needed to be a different number from the Rail company, ie Interrail. Nothing on their site, but a useful post on this forum which gave a link to activate a Pass Cover number which could be used for making reservations, starting with I for Interrail.
So back to the Blue Star Ferries site and put the new numbers in the box where the drop-down indicates it needs to be an activated Pass Cover number...but the same message pops up as before. I called the Greek number again, and the lady I spoke with had no idea what the problem was, suggesting I call again later!
How does one overcome this problem, please? Has anyone out there any advice? We are nervous about not having booked passages on ferries in peak holiday time and, having booked extremely expensive accommodation on several islands, naturally want to ensure that our ferry crossings are also sorted. Are the ferries ever totally full so foot passengers cannot buy a passage at the Blue Star Offices in Piraeus?