Avoid the harbour in high winds and definitely if a Meltemi is forecast. The anchorage NW of the harbour is very well protected as an alternative and better choice in high winds.
Near the harbour of Naousa on the south of the big bay in 15 ft. over sand and some small rocks.
Ashore: This is a very convenient spot to leave your boat and take a ferry to Santorini. We took a one day trip to Santorini that included a guide and coach (55.00 Euro/person). The town of Naousa is worth seeing especially at night with many restaurants and bars catering for all prices.