Ferry Sorrento to Amalfi

I do not know but it also depends on the weather at sea. I fortunately was able to go one yr after many yrs. wow it was special. I still am trying to ferry the cinque terra someday, also weather dependent.
Gd luck, the coast line is stunning!!!!!

Ferries usually start in April. This year, because Easter is so early (April 1), and that's kind of the start of Amalfi season, they might start earlier.

There are ferries all year to Capri. I'd check their websites to see if they also have ferries in the other direction in season and then contact them directly for specifics.