I'd be curious as to know the reason for that... Last I checked, boats in transit did not have a time limit to cross a given piece of coastline according to federal laws.
Just about all states have such laws for how long you can remain within their sovereign borders ---- without having to PAY the differential of sales taxes, etc. between what you actually paid in your 'home' state and what they demand from the citizen of that state. Same for automobiles, trucks, etc. too. BoatUS.com: Government Affairs
as for cruising sailors, Florida HAS to be the MOST UNFRIENDLY state for visiting boaters .... not only do the 'revenuers' come after you, but the FWC will be visiting you often to make sure that when swimming if you momentarily duck under the water you will get a fine if you dont have a 'divers flag', the potty police have become legal thugs (especially Volusia County), and no matter that FL has tried to make sense of the inane 'anchoring laws' the local govts. seem to enjoy ignoring such state laws and relish employing gestapo tactics including armed intimidation to board you and threaten at any time.