Currently, this route is only operated by Blue Star Ferries.
The distance from Kos to Santorini ports by ferry is 172 kilometres, that's about 107 miles or 93 nautical miles. However, the exact distance may depend on the route you take.
You can travel as a foot passenger or with your vehicle on this route.
The cheapest price for a one way crossing by foot in the summer is about 41 euros, and for a car with one person about 133.50 eurosClick Book Now and use the booking form to get the latest prices and see the real sailing dates for all ferries on the Kos - Santorini route.
I traveled in May from Kos to Santorini the port was unorganized and the ferry was delayed but the friendly port police and the ferry staff help us to board and have a pleasant trip