Co-writer/director Genndy Tartakovsky, who also directed on both of the previous Hotel Transylvania movies, supposedly drew inspiration for his screenplay (written with Austin Powers’ Michael McCullers) from a real cruise vacation, and while I assume some of the incidents here are fiction (like the giant dog who sneaks onto the ship by disguising himself with a hat and trenchcoat), the frustrations and pleasures of a real family outing are embedded in the film’s incidents.
Returning writer-director Genndy Tartakovsky, aided by new blood in the form of The Boss Baby and Austin Powers trilogy scribe Michael McCullers, simply combines the premise of Despicable Me 2 with Dracula lore to anaemic effect.