Depends on the City/County rules.
Example: Miami/Dade County
Miami-Dade County - My Neighborhood
Boat storage
Boats of less than 30 feet in length are permitted to be stored on a residential property. However, these guidelines must be followed:
They should be stored behind the front building line, behind the side street. The building line is the portion furthest from the street.
Only one boat is permitted on the property at one time.
The boat and place of storage must be kept clean and neat.
Major repairs are not permitted on the property.
The boat may not be used as living quarters and must be on a trailer for transportation.