Can I really be arrested if I violate the social distancing on the water or land?

Yes! It is a second degree misdemeanor if you violate one of the social distancing orders. As recently as this past Saturday, law enforcement officers responded to Ft. McRee where several people had gathered. The officers required the boaters to separate their boats by 50 feet. A second degree misdemeanor is the lowest crime level assigned to an offense in the state of Florida. One can be facing 60 days in the County Jail or up to 6 months probation.

https://www.leg.state.fl.us/statutes/index.cfm?App_mode=Display_Statute&URL=0300-0399/0381/Sections/0381.00315.html