FS 800.03 Exposure of sexual organs.— (1) A person commits unlawful exposure of sexual organs by: (a) Exposing or exhibiting his or her sexual organs in public or on the private premises of another, or so near thereto as to be seen from such private premises, in a vulgar or indecent manner; or (b) Being naked in public in a vulgar or indecent manner. (2)(a) Except as provided in paragraph (b), a violation of this section is a misdemeanor of the first degree, punishable as provided in s. 775.082 or s. 775.083. (b) A second or subsequent violation of this section is a felony of the third degree, punishable as provided in s. 775.082, s. 775.083, or s. 775.084. (3) The exposure of sexual organs by any of the following does not violate this section: (a) A mother breastfeeding her baby; or (b) An individual who is merely naked at any place provided or set apart for that purpose.

Note the bolded section 3(b).

Under Florida law, it is illegal to be nude in public except in a place set aside for such purpose. So, it'd be legal to be nude at Haulover Beach's clothing-optional section, but not to be running naked down the street, as a public street is not set aside for being naked.