The novelty of a man trapped in the belly of a whale threatens to swallow the deeper achievement of Brian Duffield’s Whalefall (B+): a moving exploration of the emotional depths between fathers and sons. Magnificent practical effects bring this maritime survival tale to life inside an 80-foot, 60-ton leviathan, where Austin Abrams’s imperiled protagonist must also reckon with the legacy of his salty, stubborn father, played by Josh Brolin. Well-placed flashbacks punctuate the adventure, revealing a contentious bond that gives the physical ordeal its emotional weight. The journey through the creature’s innards occasionally grows tedious, but Abrams and Brolin lend an almost spiritual dimension to two men struggling to translate love into words and actions. Their unfinished business proves as gripping as the mechanics of survival. A triumph of spectacle and emotion, the film finds an unexpectedly potent vessel for exploring generational trauma and the painful work of surfacing from it.