I have seen this too, but with a port midships discharge, I see it when on a prolonged starboard tack. The first time on a night race and an empty water bottle made a splash being dropped down the main hatch. I do have a vented loop. I have to clean the rubber piece of the anti-siphon after it happens, as the bilge contaminants will cause it to stick.
Mike Rose C&C 39 s/v Shannon Rose > Message: 6 > Date: Thu, 1 Jun 2017 09:32:42 -0400 > From: Andrew Burton <a.burton.sai...@gmail.com> > To: cnc-list@cnc-list.com > Subject: Re: Stus-List Siphoning bilge pump hose? > Message-ID: <2dab771c-26dc-4edc-b368-cedd68812...@gmail.com> > Content-Type: text/plain; charset=us-ascii > > Yup, your first thought is right; you need to install an anti-siphon > valve. Had something similar happen to me at the dock on one boat. > Floorboards started floating...and right in the middle of dinner, too. > > Andy > C&C 40 > Peregrine > > Andrew Burton > 61 W Narragansett > Newport, RI > USA 02840 > > http://sites.google.com/site/andrewburtonyachtservices/ > +401 965-5260 > > > On Jun 1, 2017, at 09:26, Joe Boyle via CnC-List <cnc-list@cnc-list.com> > wrote: > > > > We had a nasty scare last night after our Wednesday night race. We were > motoring back to the dock - about a half hour trip and I climbed down the > companionway into about 2 inches of bay water. The bilge was full and > overflowing as we motored along. Inspection revealed no leaks that i could > see from the engine compartment - shaft log, water pump, muffler and > exhaust and thru hulls were all fine. I jump up to the head and check all > 3 thru hulls there - all dry. > > > > We finally get the auto bilge pump working and pumped all the water out > - and no more leak. I believe that the float switch may have been stuck. > > > > So here's my theory - under power the 30 MK1 tends to squat and the > bilge outlet is below the water on the stern. We had had rain the week > before and I had neglected to turn on the manual switch to get out the last > of any water in the bilge - the float switch always leaves a few cupfuls in > the bilge. I am thinking that while under way with the outlet submerged, > the bilge pump cycled on. Then - as usual - the remaining water in the > hose flowed back into the bilge. But this time with the outlet underwater, > it started water siphoning into the boat. > > > > After cleaning it all up I checked it in the morning - and it was dry as > usual. The bilge hose has a high loop in it but no air break or check > valve. > > > > I am thinking a check valve or an air break would keep this from > happening again - any opinions would be welcome. > > > > Oh - and I think I will fix the manual bilge pump that I have been > putting off for a while! > > > > thanks, > > > > Joe > > _______________________________________________ > > > > This list is supported by the generous donations of our members. If you > wish to make a contribution to offset our costs, please go to: > https://www.paypal.me/stumurray > > > > All Contributions are greatly appreciated! > > >
_______________________________________________ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
