I would never call Caruso a bucket list hotel.

I see you’re going in May and I usually go in May as well as later in the summer (actually, here as I type) and I’ve always swam in May, even if some years are warmer than others. If being in the sea is important - I would think twice about Sirenuse, unless you don’t mind the public beach. Same for any other place in Ravello. Unless it’s Avino, who have their own beach club, but then you are spending at least 15 mins to get up & down.