Hi Dr L. Long time no see, but we have been traveling for 2 months with only sporatic internet access. Ironically, we were in Italy for 12 days ending last Monday. I do totally agree with your recommendations since the ferry (jetboats) are the cheapest option, very comfortable, easy, and give a great view of the Amalfi coast as they speed along the coastline. The only problem might be the schedules, but with a little flexibility it should work fine. One nice advantage is that the ferry terminal is a short walk from the cruise ship (less than 10 min). The train option is a lot more complicated since they first need to get to the Naples train station, find the right train (its on the lower level) and than deal with that SITA bus line that runs from Sorrento to Amalfi (with a stop at the top of Positano). Those SITA buses do not run as often as they should (usually about every 45 min) and they can be standing room only during the summer season. In fact, sometimes they can be full which means you have to wait for the next bus. As to the last comment about using a private car (this is how we always do the Amalfi Coast and Italy in general) I have become hesitant to recommend rental cars unless the traveler has some experience driving in Italy. Its a challenge getting through the Sorrento area (you need to do this to get to Positano) and the traffic on the Amalfi drive can be awful in the summer (it was unreal over the May 1 holiday weekend). And than the major problem is parking in Positano. In fact, we seldom drive into Positano but instead take the local Orange Bus from our hotel in Praiano (5 miles east of Positano) into Positano rather than drive our own car. One additional issue with the SITA bus (the one from Sorrento) is that it drops passengers at the top of Positano leaving them a pretty long steep stroll down into the city (its possible to transfer to a local Orange Bus to get down the hill). The ferry, drops you at the bottom of the city which is more convenient.