water tank venting problem

[tom power]

Hi All, my new old Catalina 30 1985 has a problem with the starboard water tank. When filling the tank it starts belching water back out of the filling point. The tank top is bulging with only a few gallons of water in it. I remove the vent hose on top of the tank and the excess air comes out. Has anyone had this problem. Do you know where the hose leads to? Thank you. Tom

 

[Lost Parent]

My 1982 vents on the starboard side of the hull just below the rub rail just behind fillers

 

[Stu Jackson]

Look at the base of your stanchions. Little holes for the vents.

 

[tom power]

Thank you. I'll check it out.