Gwen Stefani relaxed on the deck of a yacht off the coast of Cannes on Saturday. She wore a white bikini to chat on the phone and snap pictures of the view during her latest sun-soaked lounge session. Gwen later headed to dry land with her boys Kingston and Zuma to stroll the streets of St. Tropez. They brought along a few friends for the day trip and stopped to enjoy gelato before returning to their luxurious vessel. Gwen and her family were overseas for the Cannes Film Festival, which she attended as a L'Oréal ambassador. She and husband Gavin Rossdale hit the red carpet together for The Tree of Life screening with Brad Pitt and Angelina Jolie and later showed their charitable sides at amfAR's annual star-studded Cinema Against AIDS gala. Gwen looked glamorous solo, though, for an appearance at Sean Penn's This Must Be the Place screening on Friday.