Tank vents on a 20 center console

[amcd]

What type of vents are you running on your 20's? I have a 1973 and put a new tank and all new lines in it this past winter and added a second vent, both are located on the port side midship. For the third time this year I am having issues of saltwater getting in the vents and getting into the tank. The tank and lines have all been pressure tested and checkout perfect. The vents are facing towards the stern. I am looking to see what is recommended by others in an effort to conquer this ongoing issue!