Samir, a forty-odd crane operator in the Paris region, falls in love at first sight with Agathe, a young woman while she gets rid of a jerk trying to pick her up. Learning that she is a swimming instructor at the the Maurice Thorez swimming pool, he decides to approach her under the pretense of taking swimming lessons under her guidance. His first steps are successful and they are on the verge of giving themselves to each other when an incident happens, revealing that not only is he a good swimmer but an expert diver as well. His deception is then exposed and as Agathe hates lies and liars, reconquering her will not be a pleasure cruise.