You can take ferries from Sorrento to Positano and Naples and you can get good pictures of them from the sea. The ferry also runs to Capri from Sorrento. You can also take buses to Positano and Naples.
To get to Pompeii, take the Circumvesuviana train from Sorrento to the Pompeii Scavi stop, exit the station, turn right, and walk about 60 yards to the entrance to the ruins. Very easy.
By train between Sorrento and Pompei as well as Naples you also have the far more comfortable option of the Campania Express train. It doesn't run as often as the regular Circumvesuviana but in my opinion it's worth working your schedule around their timing: https:/…campania-express-2018-it
There is no need to pre-book any of this transportation. If you want to you can buy the tickets a day or so in advance once you are in Sorrento, if having them in hand would make you feel more comfortable.
Ferry timetables below. The ferry is a great way to travel to Positano but in recent years there has only been one direct morning ferry from Sorrento, usually at about 10:30. Some go via Capri.
I think Amalfi is also worth a visit. You can get a ferry from Positano to Amalfi for 8 euros. If you get the CTC CoachFrom Sorrento to Positano for 10 euros, keep the tickets and every other journey is 6 euros so it's 6 from Amalfi all the way back to Sorrento.
Below is my photo album of the area. Move your cursor onto each pic to see where it was taken.
More travel info
That's great! Thanks for your help!
Yes, Positano is very popular for day trippers and can get very crowded in July. We were there in early July and the queues or lines at the bus stop were going in all directions. When the Sita buses arrive, there is a bit of a mad dash to get on the bus and it's often almost full when it arrives.
Some people who cannot get on the public bus bought tickets for the CTC Coach from the ticket seller who usually appears at the bus stop about 10 to 15 minutes before the coach arrives.
We bought tickets ASAP and got on the coach no problem and it was not full but you cannot guarantee this. You cannot pre-book tickets in advance. You have to buy then on the coach or from the ticket seller, who has a big red bag. The CTC coach is also red and single-decker.
I would seriously consider taking the ferry back to Sorrento from Positano. The last one of the day departs at 5 PM, which won't cut into your day anymore than the bus since you'd need to be at the stop well before 6 PM to have a chance of getting on.
The ferry runs from April 1 to the end of October.