Gwen Stefani Gavin Rossdale couple husband wife yacht boat ponytail bikini sarong swimsuit sunglasses family Kingston Zuma

Gwen and Gavin are enjoying the sites and sounds of the Cannes Film Festival in France ... from a luxury yacht anchored just off the coast! There, they don't have to deal with annoying French fans asking for their autographs every second, they just get to relax and look hot and jet ski!

Seriously ... what a great idea -- SO much better than the crowded Croisette!

Check out Gavin with little Zuma on the jet ski; it's the cutest thing ever! Click through the entire gallery below to see the Stefani-Rossdale's vacation album (by X17) ...

Gwen Stefani Gavin Rossdale couple husband wife yacht boat ponytail bikini sarong swimsuit sunglasses family Kingston Zuma jet ski ocean water

Gwen's in town for the annual AIDS benefit hosted by amfAR at the Hotel du Cap-Eden-Roc. The L'Oreal amfAR After Party will be hosted by Gwen Stefani, Freida Pinto, Patrick Dempsey, Milla Jovovich, and Michelle Yeoh.

Partying for a cause, we like it!

Oh, and guess who'll DJ the party? Click through to find out ...