Water entering through bilge discharge

CDory23

On my last few trips in the boat (22 cruiser) I have had an annoying amount of water enter the cockpit. This is mainly when drift fishing or in rougher water where swells reach about the discharge of the bilge pump closer to the front of the boat. It is not a problem on the rear bilge as the discharge is the splashwell. I had this issue as well on my last boat as well. Even though the bilge will pump water out if/when it senses it every few minutes (rule 1100) when it kicks on it isn't quick enough to get it before the water enters through the discharge and leaves the recessed area where the bilge sets. This makes for a wet cockpit floor which is just simply annoying.

I have considered a check valve but researched that is not recommended for a bilge on the boat.

Anybody else have this problem or have any suggestions?

digger · Posted: Sun May 03, 2015 11:06 am Post subject:

Easy fix. Where the discharge enters the boat, run the hose upward a couple of inches, then loop it down to the pump. The upward loop will not let the water enter. I actually did that for the bilge, and for the fuel tank vents, after I found that I got water in my fuel tank that way also. Ron

thataway · Posted: Sun May 03, 2015 12:22 pm Post subject:

My 2006 C Dory 22 came with a check valve in the forward bilge pump. I took it out. My discharge is up fairly high, and I do have a loop even higher up when I put in a new pump and hose. The one way valves, often fail, and they restrict the water flow. The good side--when they are working, is to decrease the "dead space" in the hose--the amount of water which flows back when the pump stops.

nordicstallion · Posted: Sun May 03, 2015 1:07 pm Post subject:

When I got my 19, the deck was always awash. The previous owner put in a shut-off valve in the discharge pipe because he couldn't figure it out. It's just like a P trap under your kitchen sink but upward loop instead of downward loop.

CDory23 · Posted: Sun May 03, 2015 1:11 pm Post subject:

Thanks for the replies. That will be an easy fix to a very annoying problem.

journey on · Posted: Sun May 03, 2015 10:04 pm Post subject:

Interestingly enough, the C-Dory 25 has 3 bilge pumps. For each, the builder (whoever it was in 2005) routed the output/overboard line up above the pump intake (good), put a coil in the line at the highest point (bad) and the led the hose to an overboard discharge (mandatory.) I assume all C-Dory bilge pumps were installed in this configuration.

If not, and water entering the overboard port would just drain back through the pump and , voila, you've got a wet bilge, or cabin, or sump.

There's another aspect to having a coil of hose to prevent ingress of sea water, which I found out the hard way. If there's enough residual water in the coil the pump might not generate enough pressure/head to work. Remember, those bilge pumps are centrifugal pumps and they have a lot of clearance to pass "stuff". so they need a clear shot to the overboard fitting.

The recommended installation is to use a vented loop at the top of the overboard hose, which should be a foot or 2 above the pump outlet as shown below.

I installed several and the installation was straightforward.

Boris

hardee · Posted: Mon May 04, 2015 3:02 am Post subject:

I wonder what the typical set up is on the 22's. I'm real sure there is no vent in either of the bilge hoses on my boat. There is a bit of an elevated "hump", just don't remember seeing a vent on any sort on either line.

Harvey
SleepyC Moon

thataway · Posted: Mon May 04, 2015 7:24 pm Post subject:

I have never seen a vented bllge pump loop in a C Dory. Generally they break the siphon effect, and the water runs back down into the sump.

Siphon breakers/vents often clog up. I have had them on heads. and also on exhaust on generators etc. In some of these cases, I have gotten ride of the small valve, which plugs with salt, and vented these straight out thru the hull, up under the gunnel (not on C Dorys). With a generator, it is great, because then you have a "pea" stream out the side of the hull, confirming that the water pump is working well.

Sunbeam · Posted: Mon May 04, 2015 9:06 pm Post subject:

Wouldn't a siphon break only be necessary if the discharge through hull were below the waterline? Maybe it is on the 25, but on my 22 and others I have seen it is above the waterline. With the output above the waterline, it seems like there wouldn't be a source to "feed" a siphon.

I have an upward loop on the bilge pump hoses just inboard of the through hull to keep nuisance water (and as much of the pumped water as possible) going overboard, but I don't have a siphon break. I have had them on previous boats, say on the head discharge wherein both the head itself and the discharge through hull were below the waterline.

thataway · Posted: Mon May 04, 2015 9:48 pm Post subject:

Sunbeam, The issue, is IF the discharge can go below the waterline, when the boat is heeled during rolls. I have seen some of the bilge pump discharges too close to that point--and that is the reason I put a loop in the one which came in my boat.

Sunbeam · Posted: Mon May 04, 2015 10:22 pm Post subject:

I understand what you mean - that would be the dynamic waterline, right? In larger boats I also like a seacock on any outlet below the dynamic waterline, but not on the 22. I couldn't see (in a reasonable scenario) where the typical discharge through hull on a 22 would stay below the waterline long enough to set up a damaging siphon. Or at least I decided it was rare enough that I'd take that risk vs. the potential problem of "one more piece" in the discharge line.

But then, maybe the boat could take on water and heel to the point where that through hull would be below the waterline. I might reconsider if I kept the boat in a slip or on a mooring, too.

Also, I wouldn't be surprised if the exact "strake" location of the discharge might have varied over the years. Maybe some are in a lower strake (?).

Anyway, not trying to dissuade anyone from putting in a siphon break! I just wanted to mention my understanding that it's typically for when the through hull might be below a waterline (static or to some extent, dynamic).

hardee · Posted: Tue May 05, 2015 12:26 am Post subject:

I have been in several situations where I have heard the "gurgle" with water sloshing in the pipes. Now I'm not sure which one, the Wallas exhaust, or the midship bilge, but it was one of them. I think I was busy driving so didn't stop to see which pipe, BUT, I did check and make sure the bilge pump switch was on auto.

I have had one time on a Juan de Fuca crossing where I was taking considerable heavy spray (sheets actually) on the port side and hearing that gurgle, checked. The auto switch was off, and there was 2-3 inches of water around that aft pump. I hit ON and it took a minute or so to clear that sloshing.

Glad for the habit to check that switch anytime I hear the sloshing.

Harvey
SleepyC Moon

Dennis Meyer · Posted: Tue May 05, 2015 1:38 am Post subject:

This has been my biggest pet peeve on our 25. I've had it 5yrs now, and the carpet was soaked every time the waves picked up. It took me until now to figure out the water was coming in from the cabin bilge. I've bought some hose and will be putting in an upward rise as suggested on this thread. Hopefully my feet will stay dry in the future!!!