Day Trip from Rome to Amalfi Coast & Positano

Since you have already been there, I am puzzled at your embracing the tour (?) product. You know there is no high-speed train to Sorrento, no train of any kind to Positano, and presumably you experienced the many time-sapping delays in using multiple public transit seats to get anywhere in that area.

If you use the Search box top left, you will find plenty of comments with search terms like "Amalfi Coast from Rome". Most people think it's a futile task. I have been there only in summer, but I imagine both Sorrento and the AC are not at their best off-season. (I know there is 12-month demand from rainy places like the U.K.)

You also need to consider the immense economic impact on the world (and especially on Italy) in whatever is the aftermath of the COVID-19 pandemic. If Campania was starved for government funds since WW II was over, what will it be like when the government has no money for the northern areas? I'm in favor of supporting places that need our tourism money, but Italy may be a special case.

I'm confused as well. There is no high speed train to Sorrento. How could the cost of a train to Naples/Sorrento RT be $218 per person?
Makes no sense.

If you must visit Positano then give the trip there the time it needs- at least spend a night (2 is better)

One option is this:

Fly into Rome- go immediately to Salerno- direct trains from Rome. Stay in Salerno 2 nights. Take the ferry to Positano for the day.
Then take train from Salerno to your location in Tuscany (that part of your post is not clear either- are you renting a car? )
Finish your trip in Rome so all your Rome days are at end of trip.

Another option would be to do a guided day trip to Amalfi from Rome- there are several- Walks of Italy has one that includes Pompeii for $199 pp

I think many in Europe are considering that holidays abroad this year are unlikely to be happening. For example, many of the provisions that the U.K. government have announced this week are for a year’s duration.

As Tim and Christine have already pointed out, there is no fast-train service to the Amalfi Coast unless you're talking about a train to Salerno from Rome? From Salerno you'd have to take ferries or buses to Amalfi and Positano.

Trying to do just Rome> Salerno> Amalfi>Positano and back in a day is not a good plan to begin with - I personally wouldn't do it - but traveling onward from Positano to Siena or Florence that same day is definitely WAY too much.

Thanks all. Food for thought...not sure what we are doing yet...

Go north OR south of Rome, not both.

If this is an overnight flight, driving out of FCO not advisable, spend the night in the seaside town of Fiumicino [where the airport is located] and drive up to Tuscany in the AM [the southern part about 2.5 hours]. End the driving portion by dropping the car in Florence and a stay there. Then take the direct train from SM Novella to Salerno at 8:14 arriving at 12:14. The next ferry to [e.g.] Amalfi is at 13:00, a 10 minute walk to the Concordia dock. Amalfi back to Rome via the ferry and train.

https://www.travelmar.it/_download/orari-travelmar.pdf

Take a looks at Walks of Italy tour called “Boat hopping on the Amalfi Coast”. It seems to fit what you are looking for in a day trip.
I did the tour and it was wonderful.

Wendy, the bigger problem (as I see it) is that the OP is not intending to return to Rome. They're going onward to Siena/Tuscany/Volterra/Florence; quite a lot further so a 13-hour trip to/from Rome doesn't apply. As well, there's no guarantee that the one day set aside for this would end up being dry, sunny and/or calm, and WOI does not cancel this tour just because of rain. Under "Important Information":

"Boat rides might be cancelled if weather does not permit (ie in heavy rain). If the boat doesn’t run due to weather conditions, we will travel by private car instead."

The ferries cannot dock in Positano when seas are too rough to do so.

I see, it wasn’t quite clear to me if they were returning to Rome before heading on to Sienna and such.
Yes, I knew about the alternate plans if the ferries weren’t able to go. The seas were rough when I went but the ferries did run so we were lucky.

Luck was with you indeed, Wendy! :O)
I was going off this line from the original post regarding the onward travel plan from the A.C:

....after Amalfi will go to Siena/Tuscany/Volterra/Florence and back
to Rome.

Cissy, do I have it right?

"....after Amalfi will go to Siena/Tuscany/Volterra/Florence and back
to Rome."

Ferry and direct train from Salerno to Florence at 12:50 taking 4 hours, plus the additional time when changing hotels; car leaving Florence dropped in Chiusi, train to Rome getting off at Tibertina.

I recommended Florence first, easier from FCO.

Just got word that Delta cancelled our Oct. 6 flight; too soon to rebook for Oct. 2021. But we are getting a full refund, no hassles! Thanks to all; we will consider all your advice when we start planning for next year. Stay safe, all.