An endless stream of shark movies has swum into theaters in the more than 50 years since Jaws, and the scariest shark movie since Steven Spielberg’s 1975 masterpiece just took a bite out of HBO Max.

The shark looks phony—even Steven Spielberg knew it—but the delicate calibration of tension around it is sublime. Spielberg was only 26 when he made Jaws, and he wasn’t sure he’d be able to pull it ...