Over a month after ending his five-month relationship with Johansson, 26, the Oscar winner, 50, went shirtless in the sand and surf for the patriotic holiday. At the surprisingly buff star's side? New girlfriend Stacey Koplin, a pretty, sexy brunette who kept somewhat covered up in a thin green mini-dress.
Penn and his new lady shared a walk on the beach and hit a jetski during the beach outing.
Here's hoping Koplin fares better than Johansson. Early last month, an insider told Us Weekly that Penn broke up with Johansson because he didn't want anything "serious" since his 2010 divorce from Robin Wright. After pursuing Penn, Iron Man 2 actress Johansson (whose own divorce from Ryan Reynolds was finalized in late December) briefly moved into Penn's Malibu home.