Water under floor help required

[dnks34]

Its a bit of a Tricky one this, since buying our boat a few years ago theres always been a collection of water under the aft cabin floor, it forms a puddle against a stringer then eventually runs off into the bilge about midships. It doesnt cause any damage and we have wet vacced it out a number of times (approx 10ltrs) but it always returns so after many hours spent trying to trace a rainwater leak from above we have never really located anything and gave up on it. We have just been up to the boat today having not really used it this year and under the floor is bone dry even after all the recent downpours, so we are now thinking is this fresh water from the plumbing (which has been switched off mostly since November). We are not experiencing any extra pump noise and all the plumbing to that area is after the pump with the water tank being on the otherside of the boat and further forward. Any suggestions anyone?!

[Polly]

Nope! Looks like you are on the right track. Maybe try one water aspect at a time?

[ranworthbreeze]

Hello dkns34,

 

What about the fresh water filter, we found ours had developed a leak in the wall of the vessel, o rings on fresh water pump leaking.

 

You will have to check the pipework in that area after the fresh water system has pressurised.

The trouble with any water leakage be it on a boat or elsewhere is that water can run a long way so where it is collecting could be a long way from its source.7

 

Please let us know how you get on.

 

Regards

Alan

[dnks34]

Thanks Alan & Polly, its been present for around 5 Years on and off its just an annoyance really, I thought it was coming from the aft cleats but after removing and resetting them it didnt solve it, we have checked the rudder post and gas locker drain, rubbing strake bolts pumpout water sockets etc etc, the fresh water filter is directly above the main bilge so no luck there either. It just seems odd that its now bone dry after not using the fresh water system for a long while, one of lifes mysteries I suppose

[16E]

Fresh water filter is a good place to start.  This will normally be before the water pump so it will not make the pump cycle.

 

Shower leak 1 could it be water from the shower tray?

 

Shower leak 2 have you got a separate shower discharge pump? some boats are built so the shower tray drains into the cabin bilge and it is then eventually discharged by the 'normal' bilge pump

 

Condensation, no people equals no breathing out warm damp air, restricting condensation. 

[RayandCarole]

+1 for condensation

[dnks34]

16E we have not used the aft shower for a couple of seasons as the discharge pump stopped working and theres more room in the forward shower! Installed a new gulper type pump recently but still not used it since so I dont thinks its that. Condensation would make sense, we should have left the water pump on when we left her this time to see if it was back on next time but stupidly didnt!! If it was coming from the elements surely it would be there all the time and never dry up except for long periods of dry weather warm weather which we have certainly not been having of late!!

[ZimbiIV]

My tip next time it is dry and you are on board, squirt talc around and keep checking for water trails.

Mind you a split, I could not see without a glass, emptied 80 litres into the bilge over night.

paul

[Oddfellow]

Condensation is not that likely. 

 

What about the deck fillers and filling pipes? Could it be waste water?

 

It might be a GRP leach that is prone to opening under vibration from running the engine.

[dnks34]

Its not waste water its crystal clear and doesnt smell, i did consider waste initially tho. I might try the talc suggestion next time i go, i have checked most of the plumbing and deck fillers before but its really awkward access under floor in that area, you have to crawl round the upright calorifier and over the top of the aft waste tank, i have gotten stuck under there a few times but luckily i dont get claustraphobia!!

[Oddfellow]

Luckily, you got out!

[Viking23]

Another option could be has the boat trim changed over this time, if the water tanks are full, then the trim could change, and puddles of water on the deck might accumulate in different places, one of which could be around a deck cleat, we had this on our boat, the cleat was leaking into our outboard petrol locker, but only when the stern was low, ie bow water tank empty.

But from what has been suggested, fresh water is more likely from your water system.

You could try placing waterproof sheets or a bin liner under filters and pumps and joints of course to see what is leaking. Or kitchen roll works too, even if it dries out, you can clearly see if it has had water on it.

Regular inspection is the key.

You could fit a water sensor in that bilge area, then you know when water is starting to get in, saves regular inspections.

The biggest problem with this thread is... we all want to know where the water is coming from, so when you do find out, you must update this thread...lol

We don't like being kept in suspense lol.

[johnb]

Our water tank has a screw top which doesn't seal perfectly, if we overfill the tank, water leaks from this before it shows at the overflow point outside the boat. No idea if this could be your problem, but it's certainly ours! Hope you get it sorted.

[MauriceMynah]

I kept finding bilge water every time I lifted the engine cover off. I stopped removing the cover. Easy!

[dnks34]

I will keep hunting and let you all know if I find where its coming from!

[marshman]

If you have an aft well where does that drain to? Mine drains into the bilge to be taken out by the bilge pump - check that line if its appropriate??

[Maxwellian]

I like the talc idea. Another option that I used at home for a difficult to find leak was food dye. Talc did not work as the leak was spreading via the grout in the tiles, don't know what they used for grout. In the end I started putting food dye in the bowl to see if there was a leak and then the cistern. It was then I found it was very slowly leaking right round the back of where the close coupled cistern sits on the pan. A little bit of dirt meant it flowed slowly down the back onto the grout. When I was feeling for water it was dry. Food dye in the cistern helped me find it.

Try it in the shower drains first. If all else fails the water tank and then try the taps closest to furthest.

Standing by to be shot down and burned.

[DaveRolaves]

I have known water to get into the bilges from the joint at the top of the hull where the superstructure is bolted and sealed to the hull. The joint is usually covered by a rubbing strip and water can get under it and find its way into the hull. Dave R..........

[Mowjo]

You don't mention if the leak is when you are under way or just on the boat, the reason I mention it, is I had a similar problem on my last boat and it turned out to be the Stern gland, it was dry as a bone while sitting in the marina but under way it leaked, it only looked like a drip but after around an hour it was enough  to set the bilge pump off, I repacked it and never had a drop of water in the bilge after that,,

 

Frank,,,

[BuffaloBill]

 

 

Our water tank has a screw top which doesn't seal perfectly,

Hi John. There should be a rubber 'ring' seal on the screw cap.

Check that it's still there otherwise water from washing the boat

or rainwater can get in, washing all sorts of crap into it.

When we bought our present boat (and the one before it) the

seal was missing, so worth a look.

[dnks34]

Hi mowjo, the gland is further forward and lower than where the water collects. The main bilge on our boat is quite deep so dont think it could be water ingress when the shaft is turning as I thought it just dripped down from the bottom of the gland into the bilge, it could well be flicking off all over so its definately something i will check out more closely, thanks for that idea!

[Rincewind]

@dnks34

If you have strainer filters on the raw water line(s) check that the top(s) is(are) screwed on tight as water can leak out when the engine is running but stops as soon as the engine is still.

This was the cause of regular water appearing in our bilges...I noticed the leak one day quite by accident when our port engine was running and I was checking for something totally unrelated...

[johnb]

Thanks BB. Our leak is not on the outer filler, rather it is a screw cap on the tank inside the boat. It is like the filler hole on a normal water carrier. Really nothing could get in, as the cap covers the hole. It's just that as with boats in general it seems, water will find a way of escaping where one doesn't want it. I will make sure it is dealt with however, as it is a nuisance.

[Oddfellow]

I kept finding bilge water every time I lifted the engine cover off. I stopped removing the cover. Easy!

pmsl

[Oddfellow]

There are so many possibilities here. It could be a leaky deck fitting, poory sealed rubbing strake, maybe even a roof fitting. Perhaps it's a window that's leeching behind the internal panelling,

 

It might be water flicking up from a leaky stern gland. It could be a failed pipe from the main water tank(s) (often these are port/stb ballanced).

 

Perhaps it's a hidden and capped off but leechy skin fitting?

 

Keel Cooler?

 

Toilet flush inlet?

 

The possibilites are many and varied.