Not sure if the vent is different on your bow bag in your 2015, but the OEM vent in my 2020 works quite well. Mine is a hose connected to a fitting on the top of the bag at the extreme front. It exits out the side of the boat just in front of the driver. If I fill my back bags first, the boat pitch makes that vent the highest point on the bag so the air is pretty well bled. A check valve would help to ensure all air is removed but not essential.