We are currently (12-16 December) in Naples, and are considering taking a ferry to somewhere on the Amalfi Coast and then some sort of bus along the coast to perhaps Salerno (to avoid crazy driving), then returning (train?) to Naples - ideally in one day - anyone have experience or suggestions? Thanks!
Most ferries don’t run to the AC past October
You can check here
https://www.directferries.com/routes.htm
There's regular service to serve locals' needs between Sorrento and Capri. There may also be ferry service from Naples to Capri. It's long, weather-dependent and doesn't get you to the AC. Best to take the train from Naples to Salerno, then local SITA buses. You can download the schedules on the SITA site. There are 3 lines. Salerno-Amalfi, Amalfi-Ravello and Amalfi Sorrento (to get to Positano, for instance). Salerno is well-worth spending time in - historic center, lovely seaside promenade and you may even want to have dinner there before taking the train back to Naples.
Take the train to Sorrento and then the bus south to Positano, Amalfi, Vietri, etc.
If you purchase a time based ticket you can get on and off the bus in the different towns.
It’s a beautiful trip.
One caution about the buses? If prone to a queasy stomach, be sure to pack along a tried-and-true motion sickness reducer.
Not the cheapest, but the most practical would be to pre-book a car and driver (not a guide ...) for 6-8 hours in either Sorrento or Salerno, and take an early train from Naples to that city. Wild guess, 300 Euros. Your preferred AC stops would determine whether you pick Salerno or Sorrento. Don't try to see Positano from Salerno, or Paestum from Sorrento.