From Naples by train:
Take the Circumvesuviana (timetable) train, leaving every 30 minutes from Naples central station, in the direction of Sorrento (the last stop). In Sorrento, take a bus (Sita) in the direction of Nerano-Marina del Cantone (every hour). The bus stops just outside the Nettuno.
 

BY BUS from Rome or Naples airport
From the Airport (website) you can take a taxi and  go  the main railway station and then take a train to Sorrento, or you can go to the port  (molo beverello) and with a hydrofoil  you will be in Sorrento in just 30 minutes. Should you arrive after 10pm will be highly recommend to arrange a private transfer.
From Naples airport with bus, Curreri bus (timetable).

From Naples by car:
- Take the A3 highway towards Salerno.
- Exit at Castellamare di Stabia.
- Follow signs to Meta di Sorrento.
- After 1km, follow directions to Positano.
- On the dual carriageway, keep to the right, in the direction of S. Agata dei due Golfi – Nerano – Marina del Cantone

From Naples airport by car:
The resort can arrange a pick up services from airport.
Alternatively:
- Take a bus to the central train station.
- Take the Circumvesuviana train (leaving every 30 minutes) from Naples central train station, in the direction of Sorrento (the last stop).
- In Sorrento, every hour you can catch a bus (Sita) to Nerano-Marina del Cantone.
- The bus stops right outside the hotel.

BY HIDROFOIL FROM NAPLES
From molo beverello (in the port of Naples) you can reach Sorrento in just 30minutes by hydrofoil. (website). From the port move to the square just nearby the Cicumvesuviana station, and then take the bus "SITA" (timetable) to Nerano.