• Mobile App For Android Now Online!

    Download it here. The app is searchable in the Google Play Store under Sailboat Owners.

    Sorry iPhone/iPad users, we are still waiting on Apple. :(

    Click the X in the upper right corner to make this go away

Vent placement

Nov 7, 2012
1978 Catalina 30 Wilbur-by-the-Sea
My water tank vent is busted. Sometime in the past someone thought it wise to place it directly below the rub rail near the starboard forward portlight / fill plugs. Of course this resulted in it being smashed against the dock and now needs replacement. On the port side in roughly the same location I have a thru deck vent for my waste tank.

Should I spring for a flush mound vent and drill a bigger (1.5") hole below the rub rail or just drill another 5/8 hole in my deck and install a standard vent? I am leaning towards a deck vent but do like the look of the flush mount. One concern I have is water entry on a port tack. I tend not to be the rail in the water type but with wave action etc. it concerns me.
Jan 4, 2006
Hunter 310 Island Hunter West Vancouver, B.C.
Yes, the flush mounts are a little less prone to breakage when hitting the dock.

In the lousy photo below, the upper vent is for the water tank and the lower is an upper drain for the anchor locker. Even with the height of the water tank vent, it still has an approx. 12" loop over top of it so the deck would need to be under water before sea water would enter the tank.

It's one snug fit under the deck so the Groco fitting with an internal NPT fitting came in handy for some really tight pipe fitting.


Tom J

Sep 30, 2008
Catalina 310 Quincy, MA
In the C310, the water tank vent is in the anchor locker, well protected. Don't know if you have a similar setup on the C27.