On a budget, weigh it — Biscayne Bay Boat / Yacht Tour isn't cheap for what it is.
Group cruise ~$30–40; charters much more
A reliably great way to see Miami — skyline, cruise ships, and 'Millionaire's Row' celebrity homes from the water, with a breeze that beats the heat. The catch: the cheap Bayside cruises are narrated by a guide pointing at houses of fame that's increasingly dated, and the real magic (private charter at sunset) costs a lot more.