A snowmobile comprises a chassis including a tunnel, an engine disposed on the chassis at a forward end thereof and a seat disposed above the tunnel behind the engine. The seat has an inclined rear end face extending upwardly and rearwardly with respect to the upper surface of the tunnel, a cavity being defined beneath the seat between the inclined rear end face and the upper surface of the tunnel. The cavity is adapted to receive at least a portion of a transportable object therein, such that the transportable object is locatable above the tunnel at least partially beneath the seat.