It's been too many years (4, I think) since hubby and I sailed out of Miami, so I wouldn't feel confident in recommending a hotel (not even sure I remember the name of the hotel we stayed at)....but, I did want to give a little bit of warning of something we discovered.
As you probably know, South Beach is full of night life party revellers. We knew that, too. What we didn't know was that when the bars close in South Beach (I think that's at 2:00 a.m.) the revellers do not quietly go home to sleep....noooooooo! They make their way back to Miami....and, we found out, to an rather industrial section of Miami. Empty warehouse are "transformed" each night shortly after South Beach closes down, into makeshift discos (well, that's what they were when we were young!).
We had booked a hotel so close to the pier that we could see the entrance to the pier from the entrance to our hotel. Wooo hooo! (we thought)....about 3:00 a.m. we woke up to this loud, repetitive thumping sound. That deep sound that rattles rafters. What on earth could this be? I got up out of bed and looked out our window onto an unbelievable scene down below....hundreds of young people, dressed to the nines, entering the "empty" warehouse behind our hotel. The thumping noise was the bass from the music turned up to hearing-loss level. This did not stop until time for us to get up and have breakfast...we looked out our window again, in blissful silence, those same hundreds of young people, still dressed to the nines, filing out of the warehouse (aided by police officers!)...
I tell you this so you can be forwarned, but not to discourage you. If I were sailing out of Miami I'd book the same hotel again, if I could -- it was incredibly convenient and not expensive -- I would just take along earplugs!