IMO, Naples is always worth it, even if half a day.

That said, I would highly recommend taking the train from Sorrento to Naples, not the ferry.
- In Sorrento, unless you are staying near the ferry dock, you will need to descend the hill to get to it. Most of the town is not at the water level.
- In Naples, the train station IME is much better equipped to store luggage, hop the metro to the archeological museum, wander into Spaccanapoli, etc. There is a secure left-luggage desk at the train station.
- The Circumvesuviana commuter train runs from the terminus in Sorrento to the terminus in Naples, making it easier for you to board, find a place for you and your luggage, and not worry overly much when you descend at the end of the ride. You can then go upstairs in the station to the left luggage.
- The only down-side is then having to navigate out of Naples via rental car... I don't think driving in Sorrento would be significantly easier, though...

This thread might help you decide about navigating the Naples train station. It's old, but its OP has provided updated links at the end:
http://www.fodors.com/community/europe/through-naples-to-sorrento-or-pompei.cfm

OK, I don't know which direction you need to go from Naples and I haven't done this, so it might not work, but here goes. By taxi or Ali bus, it is easy to get from the terminal downtown Naples to the airport, which is on the outskirts of town, near major highways. There must be a car rental nearby. With luggage, I would probably take a taxi, and pick up a car at the airport where you can "hit the highway."

I love Naples, but am not sure I would do it for a half day in this situation. I might, instead use one of the days in Sorrento and make Naples a full day trip, not worrying about luggage, cars, etc., or skip it this trip. Hard call.

Good points, Sassafrass. You just reminded me that it's better to get the car rental at the airport. And on my most recent trip to the area, we went to Naples as an easy day trip via Circumvesuviana or ferry from Sorrento. (However, we also spent our last half day in Naples, having checked our bags at the termini, before getting on an afternoon train to Rome. I can't get enough of that city!)

Hi F,

>...picking up rental car and driving....<

In Naples? Highly contraindicated.

Why can't you visit Naples as a daytrip from Sorrento?

The Archaeological Museum (http://goitaly.about.com/od/naples/qt/naples_museum.htm) and http://www.museosansevero.it/index_ing.html are well worth the visit.

Sass: I love Naples, but am not sure I would do it for a half day in this situation.

This is the second time in the past couple minutes that I have strongly agreed with Sassafrass on this board. IMO, Naples is a wonderful city to explore... but you need some time to get into its rhythm.

But if I did go to Naples for only a half-day trip, I would do as ira says and visit the superb archeological museum.

I'd second, or is third, the train and airport idea!

The LLO there:
http://www.grandistazioni.it/cms/v/index.jsp?vgnextoid=ed6d9b9c72efb110VgnVCM1000003f16f90aRCRD

... and afterwards, the Alibus:
http://www.pbase.com/isolaverde/alibus

(Once at the airport, there are shuttle buses near "Arrivals" that will take you to the car rental firms' various sites nearby!)

You'd be wisest not to bring a car into Naples, or hire one within the city - not so much for the local driving, as for the huge ZTL system...

http://www.pbase.com/isolaverde/image/142204079

Try the city's visitor magazine for things to see - available for download from...

http://www.inaples.it/eng/quinapoli.htm


And perhaps have a look through the list of "Top Questions" here for other stuff that will be useful to know - as well as my 2012 version of the piece about negotiating the train station!

http://www.tripadvisor.co.uk/ShowForum-g187785-i421-Naples_Province_of_Naples_Campania.html

Photos of around the city, which does deserve more than just a few hours - if that's at all possible!

http://www.pbase.com/isolaverde/mainlynaples

Peter

Thanks for all the info. Looks like we are renting car in Sorrento and driving straight to Pescara. If we have time another day we will take train into Naples for the day.
thanks for the advice.