Advance ferry/train purchase

A ferry could be canceled because of crappy weather and the price does not change so no need to buy that before you get there. The Rome to Naples train I would book in advance to get the super sales price while supplies last, otherwise the price just goes up the longer you wait

Ferry schedules.

https://www.capri.net/en/ferry-schedule

Train timetables

https://www.trenitalia.com/tcom-en

....otherwise the price just goes up the longer you wait...... That is not quite accurate. All Italian trains except for the Regional have three levels of fares -- Super Economy, Econ, and Base. The SE and E fares are discount fares with restrictions AND -- most importantly --- are limited in number. The number available for each train vary by date and time. BUT -- Once these tickets are sold, they are no more. IF these tickets are available, they can be purchased at anytime. However, they generally sell out fairly quickly the SE. The Base ticket is the standard price and can be purchase anytime prior to the train leaving the station. Price never changes. The Base ticket is changeable at anytime with no additional fees. The Econ can be changed once but paying the current fare available. And SE can never be changed. All fares are fixed and do not change over time.

Thank you Frank, very useful information. How far in advance are the Super Economy tickets usually available?

Like all other tickets: up to the next timetable change (June 9 and December 8 in 2019).

Are you travelling after June 9? Trenitalia will start uploading the new schedules around April. Same for italotreno.it, the private competitor also running high speed trains from Roma Termini to Napoli Centrale.

We are traveling from May 27th through June 10th. Our last ticket we need to purchase for the train is on the 8th so I’ll go ahead and get those. Thank you all so much!