Samir, a tall, lanky, 40-something crane operator from Montreuil, in the outskirts of Paris, falls head over heels in love with Agathe. He discovers she is a swimming instructor at the local swimming pool, and, for lack of a better plan, he decides to enlist as her student…although he can swim perfectly. But his lie only lasts for 3 lessons, and Agathe hates liars. The truth surfaces. Agathe is furious. The end?　　 Not quite! Agathe goes to Iceland on a business trip, putting an ocean between her and Samir. But it is without reckoning with his feelings and his stubbornness… 《水中效应》的别名有：The Together Project。