Have you ever traveled by ferry in Greece? And did you buy tickets yourself? We did! And for the first time it was confusing and a lot of unknown things at once. That's why I thought I'd write you something about it so you'd have it easier at least.
Tickets can be bought online or directly from companies in a brick-and-mortar shop. Online was more accessible for us, so we started googling.

You have 2 options. You can search for a ferry in some search engine or directly on company websites. At first we bought through those search engines, because that's how we usually buy plane tickets, so why not do it the same way?
But you have to be careful what you're buying. Not everywhere is there an option to enter the correct vehicle size. For us, a significantly lower price came up, but a longer vehicle simply couldn't be entered there. And when we went to pick up tickets at the company window, we of course had to pay for everything extra... The lady explained to us that I❤️ECO doesn't belong in the category up to 4.5m (which we thought too), but also not in >4.5m. Which were the only two categories on the e-shop. Leo then tried to rationally explain to the lady that I❤️ECO does belong in the >4.5m category until she gave us at least a 20% discount! 😁
A common search engine is probably the best solution if you're traveling only with a car or without a vehicle:
- https://www.ferryscanner.com/en/ferry
- https://www.easyferry.com/en/
- https://www.ferries.gr/default.htm
Examples of individual companies - if you're a club member, have a large vehicle (like us) or already have your experience:

If you're planning some less usual voyage, it's possible the ferry only goes once a week and is operated only by some specific company. It's good to plan ahead and search so you don't end up having to wait 6 days at the port. If you don't know which company it is, then it's probably better to try entering it into a common search engine day by day. If something goes, it will search for you there and also write the name of the ship and operator.
Ticket Details
When you select the ferry you want to take - company and date, seat selection follows. There are several options. You can't stay in the vehicle, so it doesn't matter how comfortable you have it. The cheapest is a seat on deck. It's cheap - to Crete it costs around €30, but for a several-hour voyage, not very comfortable.
You can also pay extra for a better seat - so-called airplane type seat - which is basically a replica of a seat on a plane. Another option is a cabin, according to the number of beds from 1-4 berth. Further divided into with shower 'inside' and 'outside'. Since outside is more expensive and they also have TV there, I concluded it simply means a slightly more spacious room. Pets can go on deck too and for them there are designated pet-friendly cabins. And for those who like luxury, there's also a deluxe variant. Prices are of course different and range from approx. €50-150 /berth.
If you're traveling with a vehicle, you must select its size. It's only logical that you don't pay the same for a truck and a car. Transporting our vehicle from Athens to Crete for example cost €140. It's something you simply can't save on. Maybe only if you were part of the Bonus club of individual shipping companies. But otherwise the price is set and there aren't many promotions.
Even if you buy tickets online like this, you have to pick them up before departure, either at the company office or directly at the port at a window. It's something like when you fly and have to pick up your ticket somewhere. But beware, off-season the window directly at the port may not always be open! It's good to check in advance.
A Few Tips Finally
That's roughly a summary of what I've learned so far about traveling by ferry around Greece. Especially in winter season it can happen that they'll postpone your departure time due to weather... like they did for us! So instead of overnight, you go during the day. But I heard they sometimes postpone even by several days. So if you're traveling by ferry, nothing is ever certain. They won't compensate you, but after canceling the voyage they can refund the full ticket price. Better check the weather forecast too! :)

And one more small thing. If you've never been on a big ship across the sea, rather pack some Dramamine. So you don't find out about an hour after departure that you suffer from seasickness (for the first time!) and have to search for deck crew...
But otherwise I wish you beautiful experiences discovering new modes of transport! Fair winds and ahoy! Or is that not what you say on a ferry? :D