Fla. Stat. § 7.46
The boundary lines of Okaloosa County are as follows: Beginning on the Alabama state line where same is intersected by range line dividing ranges twenty-five and twenty-six west; thence east on said state line to the intersection of said state line with the range line dividing ranges twenty-one and twenty-two west; thence south on said range line to the Gulf of Mexico; thence in a westerly direction following the meanderings of said gulf, including the waters of said gulf within the jurisdiction of the State of Florida, to the line dividing ranges twenty-five and twenty-six west; thence north on said range line to the place of beginning; provided that the counties of Escambia, Santa Rosa and Okaloosa shall have concurrent jurisdiction of any offenses committed on the waters of Santa Rosa Sound.
Fla. Stat. § 7.46