A vented loop keeps the boat afloat
Issue 91 : Jul/Aug 2013
Having heard horror stories of boats sinking due to a marine toilet overflowing, I have resolved to never let that happen on our 1979 Ericson Independence 31.
A friend owned an identical boat and had an identical marine toilet, which I helped him install. I suggested at the time that he install a vented loop in the raw-water intake to prevent an accidental overflow. He chose not to go to the expense but, instead, to rely on remembering to close the seacock after each use. Despite our boats being identical, the top of his toilet bowl was 1⁄4 inch below the static waterline while mine was 1⁄4 inch above it. In my book, that’s way too close, so I fitted a vented loop in my toilet’s raw-water intake.
Over a two-week period, my friend twice left the boat for short periods of time immediately after using his new marine toilet and forgetting to close the seacock. On both occasions he returned to find the cabin sole awash and water merrily overflowing from his toilet. After the second occurrence, he asked me to help him install a loop in his boat too.
I’m about 99 percent certain that my boat can never sink from our marine toilet flowing over. I mounted a 3⁄4-inch Groco vented loop on the bulkhead behind the toilet and as close to the centerline of the boat as possible. It’s at about chest height between the raw-water seacock and the toilet.
Mounting a loop in this fashion is the opposite of its designed function, and therein lies considerable added protection against flooding. When I want to move water into the bowl, I have to place a finger over the vent hole on top of the loop. If my finger is not sealing it, that hole will suck air as I try to pull water past it with the pump. When I’m done in the head and take my finger away, the water in the loop returns to its static level. The loop is sufficiently high on the bulkhead to ensure that it always remains well above the boat’s waterline even when the boat is on a severe and sustained heel on either tack.
I have a hook installed well above the loop. A big blue towel hangs from it to hide the loop from view when it’s not in use.
Glyn Judson and his wife, Marilyn, have sailed Santa Monica Bay and the Channel Islands together since 1982, for the last 17 years on their 1979 Ericson Independence 31 that they keep in Marina del Rey, California. They always sail with Glyn’s current guide dog in training.
Thank you to Sailrite Enterprises, Inc., for providing free access to back issues of Good Old Boat through intellectual property rights. Sailrite.com
