An air intake assembly for a personal watercraft provides air to an internal combustion engine located within a hull cavity includes a housing having a generally horn-shaped configuration that includes a base and an outer end. The housing has an air passage that extends from a base to an outer end. An adaptor assembly connects the base to the hull and is arranged to form a seal around an opening in an upper portion of the hull. The adaptor assembly includes an opening aligned with the air passage. An air intake valve assembly is mounted in the opening with the valve assembly being arranged to be open to allow air flow into the hull when the upper portion of the housing points upward from a horizontal plane through the upper portion of the hull and being further arranged to close whenever the outer end of the housing has a downward pointing component.