[C320-list] Bilge pump plumbing

[John Cheek via C320-list]

I'm replacing the bilge pump and hosing, however I do not know where the
discharge line leads to.
Please help
Many thanks
John

[Michael Deslauriers via C320-list]

Hi John,

I have sail #717 and it goes out on the starboard side near the very back
of the boat. This is also where the manual bilge pump exits the boat.

Mike
"Gloria"

[Ferris Wills via C320-list]

Hi,

One suggestion: Inspect/test both your electric bilge pump (and float) as well as your manual pump - when I did this I found a sticky float switch in the bilge and a cracked rubber diaphragm on the manual pump.

I flooded my bilge (twice) to make sure both systems were working properly after the repairs.

Ferris Wills (#505)


Typos by iPhone

> On Mar 13, 2026, at 3:22 PM, John Cheek via C320-list <c320...@lists.catalina320.com> wrote:
>
> I'm replacing the bilge pump and hosing, however I do not know where the

[bruceheyman via C320-list]

Hi John,Ours has a mushroom vent just above the waterline on the transom.   Starboard side if I remember right.BruceSomerset San Pedro

[Jack Brennan via C320-list]

I've thought about installing a through hull above the waterline in the port cabin locker to eliminate the long run from the bilge to the stern.

My original setup had a 250-gallon-an hour remote pump in the port locker. The short run to the pickup in the bilge kept water from running back in, but that isn't much of a pump if things go south quickly and you have to pump a lot of water.

I installed a regular Rule pump with a check valve to keep water from running back into the bilge. I want to say it's 1,000 gallons an hour. I also rigged up a 2,000 gph pump as a portable. It clips onto the battery bank and runs a hose back into the cockpit.

The through hull would eliminate the need for the check valve, which is sometimes a little dicey because they can clog.

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.


________________________________
From: C320-list <c320-lis...@lists.catalina320.com> on behalf of bruceheyman via C320-list <c320...@lists.catalina320.com>
Sent: Saturday, March 14, 2026 10:08 AM
To: c320...@catalina320.com <c320...@catalina320.com>
Cc: bruceheyman <bruce...@cox.net>
Subject: Re: [C320-list] Bilge pump plumbing

[John Cheek via C320-list]

Thanks for the many helpful responses.

On Sat, Mar 14, 2026, 10:50 AM Jack Brennan via C320-list <

[bruceheyman via C320-list]

Hi Jack,I love the benefit of the short run from the pump to a port cabin locker and how little water would then run back in after the pump shut off.   I think the reason that Mr. Douglas ran it all the way to the back of the boat was to avoid the possibility of the ocean siphoning into the bilge when healed over on port tack.
BruceSomerset, San Pedro,CA 2000

[Greg Flanagan via C320-list]

I use my bilge pump to keep out the small amount of water that accumulates under normal conditions, and to pump out the water my dehumidifier generates in the winter. I did replace the factory diaphragm pump with an impeller pump (“the water puppy”) about 15 years ago which works perfectly.
I did have a serious (fresh) water flood while crossing the Straight of Georgia from Vancouver Island to Vancouver under 20-25 knot winds. It wasn’t pleasant. However, I used the manual pump housed in the starboard stern locker (for the first time after 18 years) to pump out the salon under sail. I was pleasantly surprised at how well this worked and the huge volume of water it pumped. I now have full confidence in this pump under severe water situations, so am not worried about the volume or outlet of the electric bilge pump.

Greg
Hoop Dancer #1076
Sidney, BC

> On Mar 14, 2026, at 2:06 PM, bruceheyman via C320-list <c320...@lists.catalina320.com> wrote:
>
>  Hi Jack,I love the benefit of the short run from the pump to a port cabin locker and how little water would then run back in after the pump shut off. I think the reason that Mr. Douglas ran it all the way to the back of the boat was to avoid the possibility of the ocean siphoning into the bilge when healed over on port tack.

[Irving Grunes via C320-list]

Consider dirty bilge water streaming down your portside

[Dave Hupe via C320-list]

Really no different than where the outlet exists on the srarboard side ....right?
Dave Hupe
1994 C320 #32

Yahoo Mail: Search, Organize, Conquer

On Sun, Mar 15, 2026 at 3:21 AM, Irving Grunes via C320-list<c320...@lists.catalina320.com> wrote: Consider dirty bilge water streaming down  your portside

[Jack Brennan via C320-list]

The way to avoid siphoning is to install a siphon break in the hose right before the through hull. We have those on other through hulls in the head, for the engine, etc.

I think hull stains are unavoidable, at least where I am. I get them from diesel cooling water as well as the AC. Not to mention stains around the bow from subtropical waters. You just gotta clean them off.

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.





________________________________

From: C320-list <c320-lis...@lists.catalina320.com> on behalf of Dave Hupe via C320-list <c320...@lists.catalina320.com>
Sent: Sunday, March 15, 2026 8:54 AM
To: c320...@catalina320.com <c320...@catalina320.com>
Cc: Dave Hupe <hoop...@yahoo.com>

[Stephen Cox via C320-list]

>

> I think hull stains are unavoidable, at least where I am. I get them from diesel cooling water as well as the AC. Not

> to mention stains around the bow from subtropical waters. You just gotta clean them off.

>

I shaped a piece of thin tube to go inside the outlet to extend the bottom of the opening about 3/16 inch and glued it in. Doesn't restrict flow but does provide a drip point for the dribbles. I think it helps.



Cheers,



Stephen Cox

Tegwen, C320 MKII #1141

[bruceheyman via C320-list]

Hi Dave,I don't think so.  It is relatively easy to sail with the port rail in the water and hence the vent under the water line.  However, it is really hard to sail with the stern continually squatting down below the water line?  A siphon break at the top of loop before it is attached to the through hull should solve the problem.Bruce2000 C320 Somerset San Pedro, CA

[ART HARDEN via C320-list]

This seems to be a lot of discussion for trying to save 10’+/- of hose.
My thoughts.
1. As mention the chances of the stern being swamped is very slim. The chances of a side discharge becoming swamped on a tack, very possible.
2. You are punching another hole in the hull. A hole can allow water in both directions.
3. In my 45 years if sailing and owning boats, I have never seen a sump discharge over the side. There must be a reason for this.
4. On small boats the hulls drain is to the rear such that if you are moving forward it will suck the water from if set up right.

Sent from my iPhone

Art Harden
Catalina 320 "Tortuga" 243
E-42
937.885.9380 (o)
937.477.5544 (m)

> On Mar 15, 2026, at 1:17 PM, bruceheyman via C320-list <c320...@lists.catalina320.com> wrote:
>  Hi Dave,I don't think so. It is relatively easy to sail with the port rail in the water and hence the vent under the water line. However, it is really hard to sail with the stern continually squatting down below the water line? A siphon break at the top of loop before it is attached to the through hull should solve the problem.Bruce2000 C320 Somerset San Pedro, CA

[Jack Brennan via C320-list]

On my boat, it's more like 20 feet of hose leading to the starboard side of the hull. That's a lot of water draining back into the bilge.

I've seen many boats with discharge through hulls on the topsides. In fact, the cooling water for my diesel discharges on the side of the hull. My old Bristol 30 pumped bilge water out of the topsides. Don Casey, the late DIY guru, talked about topside discharges as a way to limit runbacks into the bilge. He thought nine feet of hose was too much.

Take a look at the cheap through hull just above the waterline that drains the anchor locker. I've looked at that and wondered what would happen if it cracked or the relatively inaccessible hose popped off the through hull. It's on my list.

If you want to worry about holes in the hull, look at your depth sounder and knot meter. To me, the system that allows them to be removed and replaced is dangerous. It's easy to create a leak. I plugged both holes and bought a transducer that shoots through the hull.

To me, the big thing is to be aware of where all the holes and hoses are and know how to react when something goes wrong. I had the seals go on my saltwater diesel pump a couple of years ago. It's a little scary to be off 10,00 islands, 40 miles from anywhere, with water on the cabin floor. We had to wait for wind, but it was no big deal.

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.



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From: C320-list <c320-lis...@lists.catalina320.com> on behalf of ART HARDEN via C320-list <c320...@lists.catalina320.com>
Sent: Sunday, March 15, 2026 6:08 PM
To: C320...@catalina320.com <C320...@catalina320.com>
Cc: ART HARDEN <arts...@aol.com>; C320...@catalina320.com <C320...@catalina320.com>

[ART HARDEN via C320-list]

Wow!!!

No worries, these were just my thoughts. Every captain needs to know his own boat and be comfortable with it.

Sent from my iPhone

Art Harden
Catalina 320 "Tortuga" 243
E-42
937.885.9380 (o)
937.477.5544 (m)

> On Mar 15, 2026, at 9:20 PM, Jack Brennan via C320-list <c320...@lists.catalina320.com> wrote:
>
> On my boat, it's more like 20 feet of hose leading to the starboard side of the hull. That's a lot of water draining back into the bilge.