Pompeii to Positano

NOPE...you have to take the Circumvesuvian to Sorrento
http://www.eavsrl.it/web/en/content/download-train-timetable

Then the bus to Positano http://www.eavsrl.it/web/en/content/download-train-timetable

or the Ferry http://www.ok-ferry.com/

I took the train from Naples to Salerno....then the ferry along the Amalfi coast for a cost of about 12 euro. Depending upon when you are going that is in my opinion the most wonderful way to get to Positano. Also, that same ferry will take you to Amalfi and other cities for a few euros. A wonderful trip!

One word of caution: the ferries do not run to Positano during the colder months, and can't dock if the seas are rough in the warmer months so this method is not a given.

That said, ferries also run to Positano from Sorrento.

If you are with a small group it may be more convenient to share a private car service. They are about 90-120euro for Naples to Positano route and it's door to door.. We booked one to avoid dealing with luggage on multiple forms of public transport. We read the busses can get quite crowded.

Thank you all for your wise responses. So helpful and appreciated!