Back in my younger days me and all my buddies would run the chrome breathers with open element filters on our cars and trucks. True they were gassers so they may not have sucked as much air, but they were daily drivers and I never did see one fail from being wet. They must be made of the same paper money is made of, pretty tuff. I don't have any covering over my BHAF. If I did a lot of river running then I may think seriously about it, but in normal operations I don't think I'll have a problem.
Just my . 02.
Danny