Gwen Stefani kept a watchful eye on Zuma as he splashed around in the pool on a luxury yacht off the coast of Antibes today. Gwen was back in her bikini after stepping out on the deck with a shirtless Gavin Rossdale yesterday. Kingston got in on the fun riding jet skis with his dad and returned to the water for a spin on a blow-up raft with Zuma this afternoon. Gwen and the whole family are in France for the Cannes Film Festival, where she's a L'Oreal ambassador, though so far they've been enjoying their stay away from all the glamorous red carpets. There have been lots of great pictures from Cannes since the festival got underway last week, so be sure to check out all the premieres, parties, and photocalls!