I have mentioned in the past the movie Le Bossu (On Guard for the English-speaking markets), a fine French swashbuckler from twenty years ago that I like very much and used to watch every time it passed on TV hereabouts, and now have on DVD and watch at least once a year.
Great action, fine story, excellent cast.
Great movie, watch it!

In the movie, the main character, Lagardere, recalls the time when, as a Paris street urchin, he had developed a stunt that allowed him to make some money: he would ask the passers-by to toss a coin in the Seine, and he would dive behind it from a bridge, and retrieve it as it sank in the water of the river.
He even had a short rhyming song, to hook the punters.

Needless to say, Lagardere’s skill of diving from bridges and disappearing under the surface of the river will come handy later in the story.