Fla. Stat. § 7.59

The boundary lines of St. Lucie County are as follows: Beginning on the eastern boundary of the State of Florida at a point where the north section line of section thirteen, township thirty-seven south, range forty-one east, produced easterly, would intersect the same; thence westerly on the north line of said section and other sections to the northwest corner of section eighteen, township thirty-seven south, range forty-one east; thence south on the range line between ranges forty and forty-one east, to the township line between townships thirty-seven and thirty-eight south; thence west on the said township line to the range line dividing ranges thirty-six and thirty-seven east; thence north on said range line, concurrent with the east boundary of Okeechobee County, to the northwest corner of township thirty-four south, range thirty-seven east; thence east on the township line dividing townships thirty-three and thirty-four south, to the Atlantic Ocean; thence continuing easterly to the eastern boundary of the State of Florida; thence southerly along said east boundary, including the waters of the Atlantic Ocean within the jurisdiction of the State of Florida, to the place of beginning.