Is a small bit of water in the bilge okay?

[rcoleman67]

Another question, a Catalina 310 I’m looking at has water in the what I call the main bilge, just above the keel. The boat has had a previous Catalina Smile/Keel damage due to a hurricane when the boat was pushed into/onto a shallow flat. The boat was on its keel and side so caused a Catalina Smile/Keel damage. It was repaired and supposedly is good to go. That was about 4 years ago. I've read and been told that the Catalina is a "web bilge" boat... The water level is 1-2 inches, just in the very bottom, and is stagnant like it’s been there awhile. Water color is a very dark brown. I failed to get pictures so I can’t share. The keel bolts were not corroded and just looked a dark gray. There were three bilge pumps in the bilge area. Stains on the side of the bilge seemed to indicated the water level was consistent and had been there awhile The overall condition of the boat is immaculate so I was thinking it’s most likely water that has just draining into the bilge over time and just sat there as it’s below the level to trigger the bilge pumps. Other areas under the floor looked really clean. I’d eat off the floor under the engine. Thoughts? Any way to tell if this is a problem or if it’s just a small pool from whatever?

[Greatest Lakes]

If it's stagnant looking, it's been there over a week. Only way to know for sure is to drain it all out and wait.

Other option, if a bit gross, if the boat is in salt water, you can taste a tiny bit of it. If it's salty, it's seawater, if not, it's some other leak.

[flightlead404]

My boat (Hunter 38) always has an inch in the bilge, below where the pump can move it. No good way to get it out. Never tasted it, but it will get stagnant if not treated so its not cycling. The only place I have water ingress is the few drops a minute from the stuffing box when running. Other than that the only source I can see is condensation. I have no leaks anywhere else.

I toss in 2 or 3 A/C pan tablets when I'm on the boat. Keeps it fresh.

[Don C L]

I’d say the vast majority of boats you’ll see have an inch of water in the bilge. But I’d ask them to clean it out and then wait a few days with bilge pump off to see what happens. It could be as you say the bilge pumps are hiding a slow leak.

[Jebtrois]

Catalinas are notorious for taking in water through the mast. So, if it has rained since the last time the bulge was dried I would suspect this...

[dougweibel]

Depending on the boat water in the bilge can be completely normal. If the boat has a shaft, versus a sail drive, then it is not uncommon to have a bit of a leak from the shaft seal when motoring. Also many boats have refrigerator and air conditioner condensate routed into the bilge.

We don't run the air conditioner much but were running it yesterday to get the boat dried out before leaving for a couple weeks. It was fairly amazing how much water the air conditioner was pulling out of the air and depositing in the bilge - about a half gallon per hour.

While we rarely run the air conditioner we have the refrigerator on all the time. We clean out the bilge it drains into a couple times a year but that bilge pretty much always has some water in it. If we suspect a leak someone has to volunteer for the taste test as Great Lakes suggests.

[ChrisJHC]

I get a small amount of water down the mast when it rains.
Doesn’t get picked up by the bilge pump so it just sits there.
When I get annoyed enough by it, I take a small hand-spray bottle, take the top off it, put the tube part in the bilge and use that to empty it out.

[GordMay]

Originally Posted by Jebtrois

Catalinas are notorious for taking in water through the mast. So, if it has rained since the last time the bulge was dried I would suspect this...

Originally Posted by ChrisJHC

I get a small amount of water down the mast when it rains...

A common cause of [fresh] bilge water; but not likely the case, here.

I believe the Catalina 310 has a deck-stepped mast, and compression post - no penetration of deck.
FWIW: Catalina 310 Owners Manual:
➥ https://svsmitty.wordpress.com/wp-co...ers-manual.pdf
➥ https://sbo.sailboatowners.com/downl...0_70383486.pdf

[rslifkin]

A little bit of water in the bilge isn't necessarily an issue depending on why it's there. Most bilges are hard to pump perfectly dry. Some boats have effectively no water ingress to the bilge and it will eventually dry up after something has gotten it wet, while others will get some drips coming down a keel stepped mast, a few drips from a stuffing box, etc. and it's hard to keep the bilge 100% dry all the time.