Kitesurfing/Windsurfing
Windsurfing has a little more access points to the water, you can windsurf at Rickenbacker Causeway, Virginia Key or Miami Beach, which is always open. Kitesurfing is little harder and places are more restricted. Pretty much only two legal spots are Matthesson Hammock and Crandon Park. They are both pretty hallow. One of them is Ocean, the other one is in the bay. For Miami Beach, there is a spot between 23rd and 26th street, visited by locals. There is no rental service here and if you happen to find one it’ll be expensive. Best way is to bring your own equipment.