this is a lovely day trip from fort lauderdale to miami down the intracoastal waterway. even tho it takes three hrs to get to miami, the time does not feel anywhere near that long. you can sit inside or outside. inside, there are lots of open windows, and it has a top so that you don't wilt in the sun. there is a breeze on the water, which makes it cooler. there are no snacks or drinks for sale on the boat, tho, so bring your own. there is a restroom on board.
scenery includes islands, fancy houses, native plants and trees. occasionally dolphins come near the boat. one time, the boat people said, a shark came near the boat! the boat also goes under drawbridges.
the "water bus" makes the trip to miami on tuesdays and saturdays. it leaves fort lauderdale at 8:45 am, gets to pier E at marina in miami beach about 11:45 am. you have several hours to walk or take local miami transportation, see the south beach area (walkable from the marina) and elsewhere, shop, eat lunch. the "water bus" leaves for the return trip to fort lauderdale at EXACTLY 4 pm (do not be late!), gets back about 7 pm. reservations are required. cost is $18 round trip. unfortunately, i think you have to go and return on the same day (in other words, you can't spend a couple of nights in miami and come back on the next trip). but it wouldn't hurt to ask when you make your reservations!
the loading point is the stone gazebo close to the fort lauderdale grande hotel. EXACTLY where southeast 17th street meets the west side of the 17th street causeway, turn north, then IMMEDIATELY right/east (parallel to the causeway but below it). you can park all day for $8 in the hotel parking lot (see the valet guy at the hotel). the street address is 1970 southeast 17th street, fort lauderdale, FL, 33316.
for a terrific place to eat once you get to miami, see my "restaurants" tips for miami beach.
You can take a 'taxi-boat' instead of a normal cab, as much of Fort Lauderdale is water. And very expensive boats you will find anywhere!!