If you have chosen to visit Kos by boat, there are two ways to come.
One option is to come from mainland.
The boat departs from Piraeus which is the near port of Athens.
E1 is the gate of the boat to Kos (click the map). You can also call 14944 (chargeable) for more information about departure time, delays or cancellations.
For more information (timetable and tickets), click the logo (Blue Star Ferries)
Another option is to come from another island. In this case, the best way to visit Kos is to contact a local Tourist agent who will help you to plan it.