One great location just a short distance off the intracoastal waterway in Biscayne Bay is No Name Harbor. Located in a state park, it provides shelter no matter the wind direction, is deep (10' at low tide), provides great holding ground for anchors, and offers a lengthy seawall with plenty of cleats to moor up for a dinghy-free exit. And you can stay on an anchor overnight for about $20.00 (check https://www.floridastateparks.org/hours-and-fees/Cape-Florida for current rates). They don't allow overnight mooring on the seawall.
The entrance is at 25 40' 35.60" N, 80 09'53.12" W off the Cape Florida Channel, so it's easy to reach from the intracoastal or the ocean.
An added bonus, especially if you've been eating on the boat for a while, is Boater's Grill. It's at the end of the lagoon and has good food. http://www.lighthouserestaurants.com/BoatersGrill/about.php
Boater's Grill from the seawall
Entry to the harbor
Big lagoon
Sewall with plenty of cleats
