Crandon Park on Key Biscayne in Miami-Dade County is the long-standing one, with a wide flat shallow and room to launch. Matheson Hammock nearby is the same water. Fort De Soto and Sand Key in Pinellas County both work on a sea breeze. Navarre Beach in Santa Rosa County has the sound behind it, which is waist deep for a long way. In the Keys, Smathers Beach in Key West picks up the trade wind most of the winter. Winter cold fronts give the strongest and steadiest wind of the year across the whole state.
The places named in this answer.
01Crandon Park Beach
Miami-Dade County. Two miles of sand on Key Biscayne with a sandbar offshore that keeps the water calm, parking for nearly 3,000 cars, and beach wheelchairs for anybody who needs one. Parking is $7 Monday to Thursday and $10 Friday to Sunday.
Open the guide →02Matheson Hammock Park Beach
Miami-Dade County. The county's first park, on Biscayne Bay in south Miami-Dade, where the swimming is in a man-made atoll pool flushed by the tide rather than on open sand. Lifeguards on weekends and on holidays.
Open the guide →03Fort De Soto Park Beach
Pinellas County. 1,136 acres across five connected islands at the mouth of Tampa Bay, the largest park Pinellas County runs and one that takes more than 2.7 million visits a year. North Beach and East Beach give almost three miles of white sand with swim centers and food concessions.
Open the guide →04Sand Key Park Beach
Pinellas County. 95 acres at the north end of Sand Key in Clearwater, in two parts: the beach and the park behind it. White sand with seasonal lifeguards, and loggerhead turtles nest here from April through October.
Open the guide →05Navarre Beach
Santa Rosa County. About four miles of Santa Rosa Island, with swimming and surfing, and snorkeling and diving on artificial reefs set close to shore. The Navarre Beach Pier runs 1,545 feet out over the Gulf and is used by experienced anglers and beginners.
Open the guide →06Smathers Beach
Monroe County. The largest public beach in Key West, about half a mile of sand on the island's south side along State Road A1A, and about 150,000 people a year come to it.
Open the guide → More questions like this.
Flat water and something to look at. The springs and spring runs are the clearest paddling in the state - Weeki Wachee in Hernando County, Rainbow Springs in Marion, and the Wekiva at Wekiva Island in Seminole County.
Three kinds of kayaking, and Florida has all three. Mangrove backwater: Ten Thousand Islands and the Gulf Coast side of Everglades National Park in Collier County, Lovers Key in Lee, Weedon Island Preserve in Pinellas, Robinson Preserve in Manatee County.
The only living coral barrier reef in the continental United States runs down the Keys, and John Pennekamp Coral Reef State Park off Key Largo in Monroe County is where most people meet it.