I travelled to one of the nearest beaches from Florence, taking approximately 2 and half hours.
The beach was overwhelmed with people since this time is right in the middle of summer holidays, plus August is the hottest period of the year.
Upon arrival, I realise that most beaches were privately owned by hotels and landlords. Some beaches were free to use but most are restricted unless you have permission to their lands.
Overall the public and private beaches are exact same except that water sport equipments are available for hire at private beaches.