A
Alan Douglass
My 1979 Catalina 25's head system does not have a vented loop. If I use the thru-hull for discharge (beyond 3 miles offshore of course) do I have to have the vented loop? I see no signs of anything installed prior. Did Catalina not use vented loops? Can I merely close the thru-hull ball valve when sailing and not have to use the vented loop? Any advice appreciated.