Am I reading the schedule correctly? Is there only 1 departure daily from Positano that connects to Naples? 530pm departure from Positano arrival 650pm Naples.
Probably from that ferry company. There are several.
metrodelmare dot com
this is a major line with large boats. Leaves 2:15 PM from naples. ride to posi is about 1:30 to 1:45 hours. NOTE The dock in positano was under construction. I do not know if it still is. When it was/is, they will take you all the way to amalfi and you'd have to bus back. very inconvenient.