Rome to Positano

Hi there, Daryl.
Before diving into logistics, there are some things to consider?

Firstly, Positano is a long day trip from Rome involving multiple modes of transport. It's also the "off" season when daylight will be short, weather could be sketchy, some of the shops and restaurants will be closed, and the ferries will not be running to/from there. It's best done when one can stay a few days to take fuller advantage of the coast (Amalfi, Ravello, Sorrento, Capri) and nearby attractions (e.g. Pompeii, Herculaneum, etc).

Secondly, how many nights will you be staying in Rome? If fewer versus more, I wouldn't skimp on your time in the Eternal City to do this: Rome has a lot to offer. :O)

Editing to add, oops, didn't answer the time question... I figure:
Rome to Napoli Centrale vis fastest trains: a little over 1 hour

Napoli Centrale/Garibaldi to Sorrento via Circumvesuviana commuter train: 1 hr and some odd minutes
https://www.sorrentoinsider.com/en/naples-to-sorrento-train-schedule

Sorrento to Positano via SITA bus: a little under 1 hour.
https://www.sorrentoinsider.com/en/sorrento-to-positano-bus-schedule

Private drivers from Naples or Sorrento are also an option, albeit a much pricier one, and I don't think they'd save you much for time but let's see what some other posters think?

Train Rome to Naples fast train 1:10 minutes
Then Naples to Sorrento 50 minutes
Then Sorrento ferry to Positano 30 minutes and I am not sure if ferry is running in March
I think a bit much for a day but I would suggest
Naples and the Naples archeology museum
And or Herculaneum would be a worthy day trip
Long but a worthy trip

No, there's no ferry service to/from Positano in March.

"We are traveling to Italy in March and are considering taking a day trip from Rome to the Amalfi Coast."

Please reconsider.

I took a daytrip from Naples to Sorrento and Positano, and consider it one of my big travel "mistakes." These are places to be settled into and savored, not whizzed through. Coming from Rome, it will be far worse - you will spend much more of your day in travel than you will in seeing anything.

We really wanted to see that area but it does seem like a hard day of travel. Any suggestions for other day trips from Rome? We want to see as much as we can.

Again, how long (how many nights) are you staying in Rome? There is a lot to see JUST in the city.

Pompei is a long day but doable from Rome provided you leave before mid-morning. Freccia train from Roma Termini station to Naples Centrale, same station Circumvesuviana to Pompei Scavi stop. Ruins are right there.

Also the Umbrian hilltown of Orvieto is another good choice. 70 minutes by Freccia train Rome Termini to Orvieto.

We've done both in March and it may be the best time of year to do it--temperate weather, few tourists. Bag it, however, if it's rainy & cold, which can certainly happen that time of year. It would be miserable.

Enjoy your planning!

Another vote for Orvieto. Not only does it have a large, pretty historic district, it has actual sights worth going inside (which might turn out to be a good thing in March). The cathedral is very impressive (don't skimp; pay the modest fee to see the chapel), and there are at least two good museums. I don't know that they run all year 'round, but I enjoyed the walking tour conducted by the tourist office.

If you want a Pompeii like experience, Ostia Antica would be a worthwhile alternative to consider and would avoid the burdensome travel.

hey darylb
couple day trips out of rome:
lake nemi and it's wild berry/italymagazine.com a 30 minute train ride, near the popes summer home, also roman deity diana goddess of hunting, home to wild strawberry. walk the small village.
oldfrascati.com a 30 minute train ride from rome. read the blog about the family and winery, and tours that are done. frascati is well known for their white wines, small village to walk around, visit ceralli.it family owned bakery/pizza shop, "best" porchetta in the area, nonna is 92 and still baking. saw this shop on a travel tv show.
italyheaven.co.uk search calcata. a hilltop town 30 minutes north of rome known for bohemian lifestyles. artist built their studios into caves and live there, visit their galleries, couple cafes. squatters came around in the 70's (like the hippie days) this is kinda off the wall day trip that is totally different.
maybe look for street art/grafitti painted on walls or buildings. wantedinrome.com things to do list three away from the crowds in rome. so close yet so far. withlocals.com has some tours you may be interested in. enjoy your researching
aloha

Thanks for all of the great responses. I think at this point we are going to play it by ear but probably wont attempt the coast.