Rosario Dawson was back in a bikini today, hopping off a boat for a swim in the Mediterranean. She relaxed in her two-piece with friends like Luke Evans, who dove shirtless into the water. Rosario and Luke are overseas for the Cannes Film Festival, where they've been busy hitting many glamorous parties. Rosario even took a turn on the catwalk Tuesday at Naomi Campbell's Fashion For Relief fundraiser, which Luke also attended. The sexy actor has multiple projects in the works with both The Three Musketeers and Immortals coming out this year. He got into serious shape for the action films, and his buff body was on display during his leisurely day in the sun. Rosario and Luke aren't the only stars showing skin in the French Riviera, though, since Gwen Stefani and Gavin Rossdale were also spotted in their swimsuits this week.