Max is Moses who gets his tribe to the promised land but can't get their himself. And he is Christ. The hero is Moses who leads them to promised land but doesn't stay because, as a mutant with gills, water is his home. The movie translates the Mad Max movies into a story about a post-holocaust desert of water. Bartertown passes sentence on criminals through a Wheel of Fortune type spinning wheel.
People live on, and grow things on, boats.