Getting There
From Mykonos, organized guided and unguided excursions leave starting about 8:30am about four times a day Tuesday through Sunday at the harbor's west end. Every travel agency in town advertises its Delos excursions (some with guides). Individual caique owners also have signs stating their prices and schedules. The trip takes about 30 minutes and costs about 10€ ($13) round-trip; as long as you return with the boat that brought you, you can (space available) decide which return trip you want to take when you've had enough. The last boat for Mykonos usually leaves by 4pm. The site is closed on Mondays.
Carpe Diem -- Heavy seas can suddenly prevent boats docking at Delos. Follow the advice of the Roman poet Horace and Carpe Diem (Seize the day). Come here as soon as possible; if you decide to save your visit here for your last day in the area, rough seas may leave you stranded ashore.