don't know about FLa....but over here in Ala, you better hit the sand but sundown....you'll find others out there too....everything been picked over by morning......good luck.
Where I am from if you leave something on the beach and walk away theres a 90% chance it will be gone or shifted through by bums by the time you get back to it.Leave the bag at home.
Ditto the back pack. You might want to visit a store along the way and its not very easy carrying an assembled MD and wired earphones inside the store in one hand. You might want to look at something, or purchase something and you'll have to juggle your wallet. You might also meet some bikini girl that needs some help carrying her cooler.