It depends on the port you are leaving from. Some major ports (e.g. Piraeus, Naples, Valencia, etc.) are quite big. This means you may have to walk for up to 30 minutes to get from the port entrance to the departure gate.
Arriving early enough means that you won't have to worry about missing your ferry. This is why we usually advise all travelers to arrive at the port at least 1 hour in advance, regardless of whether they have collected their paper tickets or checked in online, especially if you are traveling with your vehicle.
We would also advise you to check what gate your ferry departs from, where the gate is located and what is the estimated time needed to board at the specific port. Gate information is available at the port.
Please make sure that you allow enough time for check-in and other procedures, particularly on international ferry routes. It is important to note that if you arrive late for check-in or boarding, you may not be allowed to travel. In this case, you will most likely not get a refund.
If you arrive early at the port, you will most likely be allowed to board and you will have the opportunity to explore the ferry, find comfortable seats and spend some time relaxing on-board before departure!