Apologies if this has already been posted but I've not seen it.
It appears that they're doing construction work on the dock in Positano and there will be no ferry/hydrofoil service to or from that town until the beginning of May. Exact date public boat service will resume may be TBD so keep an eye on the website:
https://www.positano.com/en/ferry-schedule
Looks like the same has been posted to a Positano public FB page:
https://www.facebook.com/groups/2362512181
Not great news for travelers basing there next month. :O(
I'd guess this will increase the numbers of tourists heading for Sorrento, Amalfi and other locations around the coast which WILL have boat service, especially sightseers wanting to go to Capri. That's just speculatin', tho.