Hi Steve, what exactly do you do when you...
flush out the vent hose? Normally, I will squirt water into the vent scupper from the outside to clean out any debris, but I really don't know that the vent hose is clear. When we first bought the boat last year it was an ordeal to first determine, then locate and unplug the vent hose and I think I've since kept it so. I would like to find a garden hose nipple that will fit over the scupper so that I know water is going through the vent hose into the tank. Just spraying it, I'm not sure.During pump out I should be able to hear air being sucked through the scupper. Maybe that would be a better time to squirt it with the water hose, that is if I have a crew.Terry