water under v-berth

Dec 6, 2020
16
Hunter 333 Prieto Marina Mandeville
I have a head scratcher. My New to Me 1998 H33.5 (likely not a 333 as stated in prior posts) has an aluminum freshwater tank and pump located under the v-berth, and the tank appears to be resting on a support of some kind an inch or two above the hull. recent inspection, I found a small amount of water that happened to be under the tank discharge and associated pvc piping to the pump (maybe a pint/quart or so?). I figured the pvc piping was leaking at the discharge or between the tank discharge and the pump, located about a foot away from the discharge. I drained the water tank to empty, removed the piping, and began to sort through the piping to check fittings etc. a short time later I noticed the same amount of water had pooled in the same spot. note: there is some type of rib or lateral structure on the hull about 2" tall and maybe 5" wide and maybe 3 or 4 feet in length across the width of hull (at that point). There is not a line or hole there to allow drainage to the bilge, so the water collects at that low spot. it is clear water.
having no water in the tank to leak, where is this water coming from?
I wet vacuumed to remove the water a couple of times and after about 30 minutes the same volume returns- not much, 2 or 3 cup fulls.

I am not aware of any water being in the anchor locker.

would this be -- "hold my breath" -- a pinhole in the hull? please say it ain't so!
the interesting part is the same volume of water recurs after I wet-vac the water and wipe hull to dry. over maybe 30 minutes a very, very small amount seems to seep from somewhere under the tank (checked with a flashlight and mirror and see there is a wet spot on hull under the "empty" water tank). The "seep" drains to the low spot, the small volume, and then apparently stops.

what are your ideas for a source for this water ? what should I check? And why would a similar volume of water return?

pictures attached for reference. the tank is maybe 2" forward of the "rib" and the pump is resting on what I am referring to as a rib.
water tank discharge and pump no. 1.jpg
water tank discharge and pump close-up.jpg
forward of the "rib"
 
May 27, 2004
1,964
Hunter 30_74-83 Ponce Inlet FL
You may have residual water in the tank that you thought was drained. The only way to be certain is to remove the pipe assembly (I have a more and very obscene name for those pipe connections) and check for water. THEN, replace the line from the tank to the pump with reinforced, vinyl hose and stainless steel hose clamps. You can guess what I think about the rest of the plumbing set up. Every joint/connection on a rigid water line on a boat is an open invitation for leaks. One reason I don't like PEX hose and fittings.
I am guessing you are in Louisiana and on salt water (brackish maybe). Wait for the next seepage and taste it. If it's fresh, it's either rain water or from the tank.
Let us know what you find.
G.
 
Last edited:
Jan 24, 2017
666
Hunter 34 Toms River Nj
]I have H34 and had similar issues with my storage locker bins under my v birth. I don’t have any water tanks in this location as you have. I would always open the lockers and find a few ounces of water in them even after drying it out.
turned out to be from condensation on the hull. Could your issue be combined condensation from the empty aluminum tank and hull?

don’t know if you have an anchor well drain like mine. I had a crack in the elbow of the drain and water would drain into that locker.

don’t think you have hull leak however one way to test that is taste the water and see if it is fresh or salt.

Hope this helps
 

Johnb

.
Jan 22, 2008
1,419
Hunter 37-cutter Richmond CA
Put some food grade dye into the tank. That will tell you if the water is coming from there.
The other obvious thing is to check if it is sea water.
There are lots of possibilities for leaks from above the fore peak.
 
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Dec 6, 2020
16
Hunter 333 Prieto Marina Mandeville
thanks to all for your responses. agree the piping has to go. when you mention "vinyl" hose, is that just a garden hose, or is there plumbing hose made of vinyl?
the head scratcher is why it seem to be the same volume of water each time over at least three cycles - wet vac to remove water, wait, and more water.

I will try your suggestions and report back.
 
Dec 6, 2020
16
Hunter 333 Prieto Marina Mandeville
You may have residual water in the tank that you thought was drained. The only way to be certain is to remove the pipe assembly (I have a more and very obscene name for those pipe connections) and check for water. THEN, replace the line from the tank to the pump with reinforced, vinyl hose and stainless steel hose clamps. You can guess what I think about the rest of the plumbing set up. Every joint/connection on a rigid water line on a boat is an open invitation for leaks. One reason I don't like PEX hose and fittings.
I am guessing you are in Louisiana and on salt water (brackish maybe). Wait for the next seepage and taste it. If it's fresh, it's either rain water or from the tank.
Let us know what you find.
G.
reinforced vinyl hose. is that a commercial grade "garden hose" or something else? thank you.
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
when you mention "vinyl" hose, is that just a garden hose, or is there plumbing hose made of vinyl?
Not Garden hose...
It is something like this.
iu.jpeg
There are different levels of product. Some more reinforced than others. Check for Marine grade product for anything beneath the water line of the boat.

Water intrusion can come from many places. You are onto of one spot related to your boat, the water tank. The usual suspects are many. A few I have discovered:
  • Aluminum water tanks have been known to develop pinhole leaks near the corner welds.
  • Fittings get cracks where they join something. Damage occurs by vibration of from being struck.
  • Hoses wear out. You have a 1998 boat. The plumbing looks to be of that vintage.
  • Once water leaks into a boat for a while it can some times move to other voids and then come back as the source is replaced. Like a bad penny. That is until the boat completely drys out.
  • You may have a deck fixture that is no longer properly bedded. The water is seeping down from above, trickling along the ceiling to a weak spot near the hull and then running down the hull to the area you are finding it in. This means you need to check the caulk/bedding material of all deck fixtures unless you can see the leaking one from inside the boat.
  • Your theory about the anchor well is also a reasonable SWAG.
I am afraid boats are destined to leak. That is until we sell them.
 
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Sep 26, 2008
546
Hunter 340 0 Wickford, RI
A friends boat 1999 340, had a similar issue. I did put some food coloring in his tank, as John suggested o you, to see if it really was his tank or another source. And just taste the water to see if it has a salty taste, that's quick and easy to do, aside from the tasting part.
In this case is was from his vent for the tank that lost its seal.
Also as jssailem said, water can linger around a while and then find its way back.
Do the simple things first, stay calm.
I hope this helps in some way.
 
Feb 27, 2004
172
Hunter 335 North East, MD
Interesting my 1994 33.5 has a plastic water tank under the v berth but the pump is in the main salon under the starboard settee near the hot water tank
 
Jun 21, 2004
2,532
Beneteau 343 Slidell, LA
I had a leak in the forward compartment on my '88 Hunter 33.5. Took a couple of years to locate it by accident. The drain hole from the anchor locker was delaminated and allowed rain water to seep between the anchor locker liner and hull. Re-glassing the hole where the delamination occurred solved the problem. Run a water hose in the anchor locker while inspecting the forward compartment for any drips / water accumulation.
 
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