My wife and I just signed up for the Mondo Guide boat tour (as endorsed by Rick Steves) of Capri (full day from Sorrento) as described at https://www.sharedtours.com/ for Fri 5 October.
You'll find great tour reviews at https://www.tripadvisor.com/Attraction_Review-g187783-d2620078-Reviews-Mondo_Guide_Day_Tours-Capri_Island_of_Capri_Province_of_Naples_Campania.html
So I'd like to encourage others who will be in Sorrento / Amalfi that week to sign up too please on 5 October so we can get a quorum! It'll be great!