Ferries from Sifnos to Koufonisi can peak at up to 2 daily sailings, Sailing frequency typically peaks in the summer months, with approximately 8 departures offered each week. While schedules may be reduced from Sifnos to Koufonisi in other seasons, ferry services are often still available.

Ferry travel from Sifnos to Koufonisi on average typically takes 3h 45m. The earliest ferry usually leaves from Sifnos at 08:50, arriving to Koufonisi at 12:30 The latest ferry departs at 13:15 and arrives at 17:15.