Cameron Diaz and Alex Rodriguez set forth on their latest day cruise from Miami today. The pair have been spending their afternoons on the water while he recuperates from knee surgery. Cameron and Alex were joined by a group of friends for today's outing, which happens to fall just one day before ARod's 36th birthday! Cameron's been keeping Alex company in Florida while production on her new film What to Expect When You're Expecting is under way in Atlanta. Her costar in the film, Jennifer Lopez, was also in South Florida over the weekend for her own birthday celebration that included some yachting, tanning, and bikinis. Cameron's bikini body got some rays earlier this week when she showed off her abs in a flirty white two-piece, which Alex seemed to appreciate.