Abstract: A vent enabling passage of air through a flexible cover such as those used to cover a boat, automobile, truck payload, stored materials at industrial sites, retail outlet outlets and the like. More specifically, the vent is of one piece unitary construction and includes an annular base secured to the flexible cover by adhesive or other conventional securing structure with the base including a central opening aligned with an opening in the flexible cover. The vent further includes a dome shaped louvered cover hingedly connected to the base and oriented in overlying relation to the base with the louvers enabling air passage through the cover and base for circulation of air in relation to the space covered by the flexible cover on which the vent is mounted. A retaining wall extends inwardly and upwardly from the base around the central opening to prevent water from entering the opening.