There is no direct ferry from Santorini to Kusadasi.
If you are going to do island hopping, you need to prepare to hope 3 to 4 islands - the easiest way is to go thru Mykonos, then from Mykonos to Ikiria, from Ikiria to Samos. Samos is the Greek isle where there is a ferry to Kusadasi.
If you are going to do island hopping, you need to prepare to hope 3 to 4 islands - the easiest way is to go thru Mykonos, then from Mykonos to Ikiria, from Ikiria to Samos. Samos is the Greek isle where there is a ferry to Kusadasi.
Link for ferries between Greece and Turkey:
http://ferries-turkey.com/turkey-greece/turkey-greece-faq-en.html