Probably with that amount of time the best bet would be to run down to the Hollywood beach boardwalk. It is about 15-20m drive, south Route 1 to Sheridan, East to A1A and park south of the marriot a couple of blocks. Depending on the time of day you can catch a beer and something to eat sitting right on the beach. Heading north to Ft Lauderdale beach would probably take at least 30m and all of the resturants are across A1A not right on the beach