Transfer time to Transvesuviana at Naples

I've never heard of a TV as you call it. There is a commuter rail train from Napoli to Sorrento which takes about an hour and runs about twice an hour. It is called the Circumvesuviana. If that's the one you mean, and if you have no ticket issues, it might take you about 10 minutes. I don't know how much luggage you will have nor how fast you perambulate.

Sam, As Nigel mentioned, it's likely the Circumvesuviana that you're referring to. "Transvesuviana" is somewhat of a translation, but I've never seen that used. Once you disembark from the Freccia train at Napoli Centrale, I'd be surprised if it even takes 10 minutes to walk downstairs to the other station. Note that the Circumvesuviana has several lines, and Sorrento is the last station on that line (you'll pass Pompeii on the way). Be sure to wear Money Belts and watch your luggage! You may find the appearance of the Circumvesuviana trains a bit "unusual", but they will get you to Sorrento. I often characterize them as "graffiti laden clunkers". Happy travels!

Sam , one other small point , before you descend the stairs to the platform
( binario ) stop somewhere in a tabbachi or tobacco - newstand and get tickets . If I remember they are about 4 euro each. There is a shop on the left just before you go downstairs .

I'm pretty sure you buy tickets to the CV at a ticket booth at the top of the stairs, not at a tabacchi. At least that's how I remember it.

Thank you all for your information and for your corrections as to the proper name. I had planned on at least 45 minutes for the transfer. I don't think I'll be too surprised with the appearance of the train as I spent a fair amount of time on the New York subway system in the 80's.

The appearance of the train is no big deal. It looks like any other commuter train you'd find in the Northeast U.S. I would allow about 20-30 minutes to make the transfer, just because the Naples train station can be confusing and you do need to sort out which train you should board.

At most thirty minutes and that is probably too much. I seem to remember when you get off train from Rome and face the exit from the station the ticket booth for train to Sorrento will be to your right just before the stairs down to train.

Before you go downstairs to the track, make sure you're taking the correct staircase - the setup of the tracks will force you to backtrack if you make a mistake. There is adequate signage overhead, just double-check it.