A unitized fuel vapor separator and evaporative emission device; marine fuel system, and marine engine therewith are provided. The device includes a fuel vapor separator and evaporative emissions chamber having a common wall separating the fuel vapor separator from the evaporative emissions chamber. The fuel vapor separator is configured for fluid communication with an upstream fuel tank and with a fuel pump and has a fuel vapor outlet to channel fuel vapor outwardly therefrom. The evaporative emissions chamber is configured for fluid communication with the fuel tank to receive fuel vapor therefrom and has an adsorption material for adsorbing fuel vapor and dissipating air from the fuel vapor through an air outlet to channel the air outwardly therefrom.