Chelsea McMullan’s documentary “Swan Song” details the mounting of “Swan Lake” by the National Ballet of Canada under the auspices of Karen Kain. Fans of the artform might recognize the name: Ms. Kain was the company’s principal dancer in 1971. 

Rudolf Nureyev was an early booster and Ms. Kain danced the world over, including at prestigious Moscow, London, Moscow, New York, and Paris venues. She also had her portrait painted by Andy Warhol, a tribute for which Ms. Kain has mixed feelings. Still, there it is, hanging in her living room.

Ms. Kain is at the center of a whirlwind of activity that is part-and-parcel of collaborative art. The film’s title winks-and-nods at both Tchaikovsky’s ballet and Ms. Kain’s oncoming retirement: “Swan Lake” will be her final production as the company’s director. Notwithstanding the slew of awards Ms. Kain has received during her lifetime, it is this variation on a venerable (and popular) property that she takes on as a legacy project. Ms. McMullan started work on the movie in February 2020. Then Covid hit.

So much for the best-laid plans of mice, men, and ballerinas. Two years later, “Swan Lake” up-and-started again with a camera crew ensconced amid the company and Ms. Kain fretting about the myriad things a director has to fret about. Ms. McMullan singles out a handful of dancers at various stages of their careers and with various concerns at hand: failing bodies, fragile psyches, youthful indulgences, ideological begrudgement, and ego, ego, ego. All of which is ultimately subsumed by the vagaries of performance.

Did you know that art has a way of humbling the artists involved in it? Ms. Kain does, even if her charges aren’t altogether wise to that home truth. “Swan Song” is a testament to the benefits of experience and hindsight.

Steven Speilberg’s “Jaws” (1975) struck such a primal chord in the human psyche — let’s call it a recognition of our fragile standing in the natural world — that the innumerable sequels, rip-offs, and riffs in its wake make a kind of anthropological sense. That, and there’s money to be made in them thar sharks. 

While only the most masochistic of film critics would want to keep track of them all, let’s say a word for Joachim Hedén’s “The Last Breath,” a shark picture whose by-the-book plot is mitigated by a swift efficiency of craft. A group of college chums get together for a reunion on an unnamed tropical isle and end up trawling through the underwater wreckage of an American warship. 

They do so to pay off the debt run-up by their captain, an old sea dog named Levi (Julian Sands in his last role). The wreck is labyrinthian, filled with air pockets and the domain of a particularly vicious shark or two. That a couple of our protagonists are not up to snuff on their diving skills does not augur well.

Mr. Hedén, along with cinematographer Eric Börjeson and a superb visual effects team, have crafted an underwater thriller that is, in its scenic particulars and spatial complexity, cunning. Never for a moment are we left to question the claustrophobic authenticity of the surroundings or the tangibility of the sharks in question. 

Those with a fear of the ocean depths and its inhabitants have been warned. Those with a fear of stock characters and contrived heroics, too, have been warned. Still, “Last Breath” is impressive enough to guarantee its cast and crew employment for some time to come.