Lady Gaga went from sexy beach photo shoot to a wet dress contest in the blink of a wave -- and she didn't have much on underneath.
Gaga had several wardrobe changes in the sand Wednesday in the 'Bu -- going from French dominatrix to sea nymph ... with her ass on full display much of the time.
Not to worry ... when the waves crashed, Gaga had several people waiting on her hand and foot. To the photog who also got dunked, we say ... thongs for the perfect shots!