Water in bilge

[Ozz043]

Hi there.
I've got an annoying problem with water in the forward bilge, 1999 Marlin.
With the boat in Marina I drain out the water manually, sponge in bone dry ...
Over the following day or two it comes in to the same height every time, no more, no less ?
This height is at the tip of the head sea cock handles when turned off ( always off when not in use )
This level seems to be below waterline ??
I cannot see any leakage from any thruhull fitting, I even drained the fresh water ... No change

It's doing my head in please help ! :hmm

Ozzie from down under !

 

[Fishtales]

I find that water collects and settles in the forward bilge when the boat is at rest. Underway, it will likely run aft. When you return to the dock, it should want to run forward. When are you evacuating the bilge? Is it the last thing you do before leaving the boat?
I'd first ensure that the under the mid birth and aft bilge areas are dry and that there is no blockage in the tube that allows water to run fore/aft. Just thinking if this was blocked to some degree and there is water in the bilge it would take a while for it to make it up to the forward bilge. So you get it dry and then it appears in a day or two...
Second, is the water salt or fresh? Does it appear after rain or washing? The anchor rode drains into the fore bilge so if wet or if you wash it down with freshwater at the dock, it will collect in the fore bilge.
Third, is water getting in via the windows, hardtop mount points or some other way? When you wash down the boat, is water somehow getting into the bilge? Some of the cup holders drain into the bilge as does the floor drains in the cabin for instance. Are the deck sections and plates sealed properly?

 

[suzukidave]

i agree on gravity reasserting itself after a run as one possibility.

it could also be a gradual leak being maintained at a fixed maximum level by the automatic bilge switch trigger point. likely the aft bilge pump is controlling the depth.

if you have redundant bilge pumps and switches in the stern, test that both are working, then turn off the lower bilge to see if the water level rises over a day or two to the point of the higher switch. if it does rise, you have a problem.

if it does not rise, reconnect the lower bilge and you can either ignore the water or relocate the bilge switch to a lower point.

 

[Ozz043]

Thanks for your response guys, she doesn't take on any water underway or when washing, very minimal amount anyway. She's in the marina, dry aft bilge and I remove all of the water manually...Agreed the water tends to gather forward and it slowly dribbles through but from where ? Under the fuel tanks ?.. I'm not sure whether it's fresh or salt water...I just can't see a leak anywhere which is frustrating!

I hadn't thought of the leak being more than what I am seeing .... As in the bilge pump leaving or maintaining this amount because it can't pump anymore ....

I will try filling with fresh water from the aft, watch it dribble through and let the bilge operate under normal conditions then see what the level is once it shuts off ...BUT...this still doesn't help me find the leak :hmm

I've checked the three sea cocks aft, the transducer and temp probe, the two sea cocks midships for the head, the bow thruster....all dry. No idea besides a cracked hull....PLEASE NO !

Aussie down under

 

[fishbust]

Up to the handle on multiple locations tells me it is not just water in bilge just settling forward, repeatedly.

There are a lot of places a Grady (or any fishy boat) can leak from below or above. Check all of those waterline thru hull fittings/hoses for fishwell drains, cockpit scuppers, livewell, sinks if you have been using them, etc.

For more water intrusion possibilities, also check the rear hatches on your bracket/euro-transom. Water washing/splashing up while boating could be leaking by the O-rings. This could be a leak from above. All those inspection hatch O-rings need to be replaced once in a while. Every single one of mine on my boat was shot and needing cleaning and replacing. I completely removed my aft pop out hatches and replaced them with the screw in type. Wet the O-rings with super lube or something when closing them.

 

[SmokyMtnGrady]

As mentioned before there are a few areas where washing the boat or rain water can dribble in here or there into the boat and get into the bilge. If you do not want to taste the water and honestly who would right? Go to your local aquarium store and buy a hyrdometer. Use a clean sponge (new never been used) and soak up the water and squeeze it out into the hydrometer and that will tell you if it is fresh or seawater. Salinity of seawater will read anywhere from 1.22 to 1.29 on an aquarium hydrometer. If it reads less than that especially anything below 1.10 you can bet the source is from rain or washing or perhaps your freshwater system. Clearly some seawater will get in from time to time and when it does some salt residue is left behind and I would suspect it will show up on the hydrometer. Hydrometers here in the states are like $8 to $10. This information is key to your search here.

 

[sampeeter]

thanks to all for answering

 

[suzukidave]

one other place you can check for water is the fuel tank compartment. the inspection plate o-rings and/or the caulk around the coffin lid can fail and let water in there.

don't know for sure on a marlin but i believe there will be a pvc drain pipe that runs under the fuel tank connecting the forward and aft bilges but sealed off from the fuel compartment and then an open drain through the bulkhead in the back of the fuel compartment into the aft bilge. the pvc pipe sometimes cracks and both drains can get clogged.

 

[Fishtales]

another area to check is freshwater systems. under pressure they could be leaking. that would be easy to find with some food coloring.

 

[Another Distraction]

You'll find it, but you need to see if it's salt or fresh water first. That's #1. Taste it!!! Boil it off and see what's left.

Did you remove the big 4'x 2' hatch from the stern cockpit? Did you remove the large 2' x1 ' cabin floor hatch? The large hatch in front of the outboards? You're gonna have to dive deep with good light and a shop vac to find it. Looking through round deck hatches won't work well.

Block the PVC pipe that runs between the forward and aft and then it may help you see what neighborhood the leak is from. Forward or aft.

 

[journeyman]

Bob, I think you mean 1.022

I was interested in your idea (it's a great one by the way!). It would be a good tool to have around the boat. I did some "Googling" to find out more about it and what the scale was. I think I'll pick one up and keep it in the dock box.

 

[SmokyMtnGrady]

journeyman, you are correct. I keep an 80 gallon saltwater aquarium and I missed the reading on this (lol). I tend to think the guy is just collecting wash and rain water, but I could be wrong and a little test using the hydrometer will give him a piece of mind or bring some heartache unfortunately if it is seawater.

 

[Ozz043]

Wow what a response, thanks guys !

I've searched high and low, Ive taken off the hatches and had a good look with a torch, I've filled with fresh water from the stern. All conduits are clear flowing, not blocked, I've changed all inspection caps to the screw type and sikaflexed in properly.

I've fully drained the fresh water and yep it still came in so its salt...

Great idea testing the water PH ! No way was I going to taste it...what if it was from the head tank YUK..
Great idea blocking the conduits too, that isolates the sections..

I hate to say it fells but I found the leak ! Embarrassing as it was right there in plain sight...it was on the sea dock from the head tank discharge, the slowish leak from the thread on the underside of the valve...

When I was scooping out the water the sea ok would get wet, I'd sponge it dry, but not totally dry it.. :-|
Once I did that...WELL...I saw it didn't I.
Many thanks to all who've responded, I've learned some tricks along the way so ally not lost !!
Ozzie down under ...

 

[SmokyMtnGrady]

Glad you found the leak and it was something simple. A hydrometer measures how dense or the salt content in water. On the other hand pH is the unit of measurement to gauge how acidic or alkaline a fluid may be. Some folks may not be all geeky about such thing, but given in the context of determining if the leak comes from rain or washing versus below the waterline, a hydrometer would be the preferred tool to use. Though one could test the pH and typically seawater runs more alkaline around 7.9 to 8.2 where as freshwater typically leans to neutral to acidic 7.0 to 6.9 to 6.8. So pH could be used I guess but measuring the salinity of the water is the best way to go. It is difficult to write a clarification without sounding snobby or in a way where one does not seem to make another look or feel stupid. I truly do not want either here. I want others who may not know exactly what is being written to confuse the two.

 

[sampeeter]

Rain water is softer than hose water and will always find a leak. A little soap in a garden sprayer will break the surface tension and allow the hose water to find the leak. Think of it as wetter water.

 

[suzukidave]

i can't wait to see what other random stuff sampeeter is going to copy and paste for us soon.

http://forum.chaparralboats.com/index.p ... opic=21987