At least between HHI and Key Biscayne there are few places I would. Mostly it's brown, very dirty, often tannic, and probably has a lot more pollutants.
On the
cruise I just finished I was watching for places I'd make water, as I'm planning a
water maker this year.
About the only places I'd consider it would be in inlets with a significant tidal flush, and only on an incoming tide. Places like St. Catherines, St. Mary's, St. John's, Fort Piece,
Lake Worth and only in the inlet on an incoming tide.