I spoke to the Park Manager today. He told me the following:
The park has been unusually crowded perhaps due to the high cost of gasoline. Remember there are almost 2,500,000 people within Miami-Dade County alone.
They tried to have kiteboarding along with normal bather traffic on Easter Weekend. Due to the substantial quantity of people and encroachment on the launching area it was a major management problem for the Park and Lifeguards.
He told me as a result, they have gone back to the procedure from years past, allowing registered kiteboarders with helmets that sign in to ride Monday through Friday and NOT on Saturday or Sunday until after Labor Day Weekend (September 3?). Many will recall that this policy was in force for several years (3?) until things were relaxed a while back.
Riders still need to register, sign in and wear helmets. A complete listing of the rules
appears here
He also told me that Miami-Dade PD will be recovering kites and bags left of the beach by folks coming in by boat on weekends and taking them to the park office. Boats are required to stay at least 300 ft. off the beach.