From this link written in 2003 are some exerpts. I know it's a little long and we're all a little tired reading all the legal stuff but I've bolded key points to help make it easier to see the point that I will be making at the end as it applies to the current situation in Destin.
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"The City of Destin has been grappling with the beach turf wars for the past few years, trying to keep the beachfront landowners happy and trying to satisfy the need to preserve the publics access to the beach. During 1999 and 2000, there were three ordinances proposed to address the public beach access problems:
Beach Management Ordinance
Pedestrian Zone Ordinance
Dry-Sand Buffer Zone Ordinance
[FONT=CenturySchoolbook,Italic]1. The Beach Management Ordinance[/FONT]
The proposed beach management ordinance applied to beach concessionaires and vendors. This ordinance restricted the ability of beach vendors to set up umbrellas and chairs (known as beach set-ups") close to the waters edge to avoid blocking the publics lateral access along the beaches.62 The Destin City Council unanimously passed the beach management ordinance, prohibiting rental beach set-ups within twenty feet of the water, applying only east of Henderson Beach State Park where the beaches are narrower.
[FONT=CenturySchoolbook,Italic]2. The Pedestrian Zone Ordinance[/FONT]
The proposed pedestrian zone ordinance, proposed by beachfront landowners as a compromise, established a ten-foot area for pedestrian lateral access along the beach, additionally prohibiting beach set-ups in the pedestrian zone. This ordinance was to be implemented by the landowners voluntarily granting easements to the City of Destin.However, after public comments that the ordinance could effect a taking, the ordinance was superfluous, and the ordinance could create enforcement problems, the proposed ordinance failed to pass for lack of legislative sponsorship.
[FONT=CenturySchoolbook,Italic]3. The Dry Sand Buffer Zone Ordinance
The proposed dry-sand buffer zone ordinance was based on Florida's doctrine of customary usage announced in [FONT=CenturySchoolbook,Italic]Tona-Rama [/FONT]and proposed by the Destin City Land Use Attorney.This ordinance carved out a twenty-five foot buffer zone from the most seaward permanent structure on the private beach while leaving the rest open for public use. Attempts were made by the Destin City [/FONT]Land Use Attorney to build a record and collect information concerning the publics customary use of the each. Specifically, the City sought historical and archaeological information to
establish that the beach had been used by the public for time immemorial. The ordinance received opposition from private beachfront landowners, coupled with threats of litigation from the Southeastern Legal Foundation, Inc. to the Destin City Council that it would fight the City if the ordinance passed.After numerous fact-gathering workshops and public comments voicing concern over this ordinance, the ordinance failed to pass.
[FONT=CenturySchoolbook,Italic]B. No Disturbances, No Harm
Instead of opting to pass a pedestrian zone ordinance or a dry sand buffer ordinance to deal with the beach turf wars, the City of Destin decided to leave the issue to the Okaloosa County Sheriffs Office.72 The Sheriffs Office uses the debris line in the sand as a surrogate for the mean high water line, allowing the public leeway of ten to fifteen feet landward.If the public beachgoer goes ten to fifteen feet landward of the debris line and is not creating a disturbance or misconduct, he is left alone.However, if the public beachgoer goes ten to fifteen feet landward of the debris line and the private beachfront property owner asks the Sheriffs Office to ask the party to leave, then the deputies will ask the public beachgoer to leave.If the public beachgoer refuses, then he will be given a Notice to Appear in court.
The Destin City Council, although interested in finding a compromise for beachfront property owners and the public, was likely worried most about the possible cost of litigation if they were to pass the dry-sand buffer zone ordinance. Small local governments, such as Destin, do not have the financial resources to battle large public policy interest groups that have bottomless spending accounts, even if the ordinance is supported by the doctrine of customary use announced in [FONT=CenturySchoolbook,Italic]City of Daytona Beach v. Tona-Rama, Inc.[/FONT]
In 2002, the Destin City Mayor and Okaloosa County Sheriff requested an advisory opinion from the Office of the Attorney General for the State of Floridaregarding the beach management ordinance, doctrine of customary use, and use of the Sheriffs Office in enforcement.The Attorney General for the State of Florida responded:
[ ] The City of Destin may regulate in a reasonable
manner the beach within its corporate limits to protect the public health, safety, and welfare. This regulation must have a rational relation to and be reasonably designed to accomplish a purpose necessary for the protection of the public. The city may not exercise its police power in an arbitrary, capricious, or unreasonable manner. Such regulation may be accomplished regardless of the ownership of this area, with the exception of state ownership, and without regard to whether the public has been expressly or impliedly allowed to use that area of the beach by a private property owner who may hold title to the property.
[ ] The right of a municipality to regulate and control dry sand beach property within its municipal boundaries is not dependent on the finding of the Florida Supreme Court in City of Daytona Beach v. Tona-Rama, Inc.
[ ] Private property owners who hold title to dry sand areas of the beach falling within the jurisdictional limits of the City of Destin may utilize local law enforcement for purposes of reporting incidents of trespass as they occur.
The citys beach management ordinance
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does not expressly specify that it be applied only on public land or land on which the public has been expressly granted a right of use and access [T]he ordinance as written applies to all areas falling within the definition of beach, regardless of whether such areas are located on public or private property and regardless of whether the public has been expressly or impliedly allowed to use such areas by a private property owner.
The Attorney General advised that whether th[e] customary right of use [announced in [FONT=CenturySchoolbook,Italic]City of Daytona Beach v. Tona-Rama, Inc.] exists in a particular piece of property is a mixed question of law and fact that must be resolved judicially.
In his advisory opinion, the Attorney General recognized the importance of the common-law doctrine of customary use and opined that it may be relied on for [FONT=CenturySchoolbook,Italic]ad hoc determinations of the degree of customary and ancient use of the beach.85 Finally, the Attorney General stated that:[/FONT]
private property owners who hold title to dry sand
areas of the beach falling within the jurisdictional limits of the City of Destin may utilize local law enforcement for purposes of reporting incidents of trespass upon their property [FONT=CenturySchoolbook,Italic]on a case-by-case basis
. However, local law enforcement officers may not be pre-authorized to act as agents of private landowners for the purpose of communicating orders to leave private property to alleged trespasses
It is still to be determined what this means for the preservation of the publics right of beach access. By keeping the dry-sand area buffer zone ordinance off the ordinance books, the City appeases the private beachfront property owners. Additionally, by relaxing the enforcement of its trespass law using local law enforcement on a case-by-case basis, the City calms the public's fear of legal action from frolicking too far landward of the debris line. Although at this time Destin has declined an invitation into the litigious side of determining the scope of the doctrine of customary use, the City of Destin, as a test case, is the second element that creates "the perfect storm" for Florida to test the strength of its policy of preserving public beach access."
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Here's my take on the situation in Destin: It certainly appears that they have an "ordinance" that doesn't really exist (never legally adopted). They have turned over any trespass interpretation over to the Sheriff's department.
I guess you could call the policy, "Destin's desire for the beach to be public near the water line so everyone can use it even though Destin hasn't proved it in court yet on a case by case basis and know that the Florida attorney general won't back Destin".
But the Florida's attorney general states that the sheriff MUST arrest a person if that person is on private property and is told to leave by the owner and does not (from above)....private property owners who hold title to dry sand areas of the beach falling within the jurisdictional limits of the City of Destin may utilize local law enforcement for purposes of reporting incidents of trespass upon their property [FONT=CenturySchoolbook,Italic]on a case-by-case basis[/FONT]
Am I missing something?
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). If the judge ultimately rules against you, then from everything everyone is "told" by Destin, you would have grounds to sue Destin for advising the public that they have the right to walk, lounge, fish, etc. on the the "20 foot" section of dry beach even though it is on private property.
In fact, it sort of implies that the beach is public, why else would you worry about a public access? Just so you could keep going, trudging through the wet sand to somewhere else? But it isn't spelled out. 
An attorney might have fun with this, though.