A3 275 then GQ 348 at Athens
Chios → Athens → Santorini
Timetable, Athens time
17:00A3 275 from Chios at the gate
13:30GQ 348 to Santorini leaves the gate
20 h 30 apart on the timetable, overnight
GQ 348 leaves 20 h 30 after A3 275 arrives on the timetable: more than half a day, so not a connection we count.