Hunter 306 fresh water leak

[Arbee]

We've owned our beloved 306 for 4 years now and it's been a very dry boat (since I had a PSS fitted) and I really like it that way. In recent weeks we've started to get about a cup of fresh water (tasted it, just clean fresh water) in the bilge between visits (we're on board at least every second week).

I've checked coolant, all good (engine full and overflow reservoir half full as usual). I've check plumbing from the water tank in the v-berth all the way back and water heater, all good (and the system holds pressure fine). So, maybe condensation from the fridge drain, but there's really too much for that. The last remaining culprit - rain, and we have had some heavy storms of late, but I have no idea where it's getting in. The v-berth is dry, the stern channel under the cockpit is dry, every locker is dry. There are no visible streams of water running down into the bilge or from any of the pipes that feed it. It seems to be focused in the mid-ships area and possibly originates under the head floor, into the shallow rear bilge and then into the deep mid and forward bilge. That's where the water has pooled anyway. Any clues, tips or previous experience with this mystery will be much appreciated!

Thanks, Robert
Charisma, 2004 Hunter 306, Westernport Marina
Vic, Australia

 

[jssailem]

Hi Robert. Sounds like you need to become a water detective. Finding water leaks can be frustrating.
Subject: Identify- is the culprit fresh, foul or salt water?

Investigate: Water tends to flow down hill, if fresh it is coming from above or the sides. Look at the places that fixtures may puncture the fiberglass skin of the boat.

Or. If the water is salty could one of the through hulls be leaking. Check hoses then the valves.

A third possibility is the water being held in the boat or manufactured by the boat both fresh or foul. Examples include condensation, freshwater tanks, drains, and foul water tanks.

Good luck.

 

[Arbee]

Apologies, I put fresh water in the thread title but didn't repeat it in the post itself (I'll edit the post for clarity). It's fresh water, tastes like fresh water (no oiliness, coolant or waste taint) and the plumbing all checks out and the pressure holds. Rain is the only thing that makes any sense to me at the moment but I can't locate a point of ingress except to say it "seems" mid-ships starboard side somewhere. The v-berth, stern channel under the cockpit, engine floor and all the lockers everywhere are bone dry.

Thanks

 

[Crazy Dave Condon]

Water leaks sometimes is hard to find. As a former Hunter dealer now retired, you need to pressurize the cabin and find air bubbling out from the cabin and deck.
Close everything up. Tape off the forward hatch. Then tape off the entire companionway with a solid piece of plastic. Put a small slit in the plastic and insert the tube from a leaf blower and tape the plastic to the tube. Turn on leaf blower.

Have someone brush on soapy water from a bucket on all fittings, chain plates, rub rail, etc. Where you find air bubbling out, there you will find those leaks.

in 2008, I drove six hours to Chattanooga TN and found a leak within minutes. There was no caulk between the hull to deck joint on a 306 in one place. Repaired that leak finding no other leaks

 

[Arbee]

Thanks Dave, the starboard side where the water appears to be coming from is our docking side (and boarding side), so mid-ships there certainly gets more pressure on cleats, staunchions etc. and your advice makes great sense.

 

[Crazy Dave Condon]

You are welcome

 

[jdrutten]

My h306 has a port-side midship leak, and if the rain comes in at the right angle and intensity, I get a nice defiant stream of water that drips from the interior plastic side panels right onto the shelf behind the settee. It's fairly dependable, so I leave a little plastic wastebasket there to catch the water. First thing I do when I return to the boat is to check the wastebasket to see how much rain we got. I haven't gotten around to the pressurized cabin test yet, but when I do (hopefully this spring, pending other projects) will be paying special attention to the jib tracks and other nearby deck hardware. It wouldn't bother me in the least if @Crazy Dave Condon drove out to my boat and found my leak in 5 minutes.

 

[Crazy Dave Condon]

Brush all sealed windows too. I am ready for takeoff to cold country. Wait it’s cold here too up on my mountain too

 

[Gripper]

David, your pressurization idea sounds perfect. Right now in Southern California. We are getting inundated with tons of rain. I have a leak that drips from the light directly above my table. I have a 1997 40.5 legend. I suspect that the water is leaking from the hold down screws for the cover plate located aft of the windshield. I will wait until it stops. Raining here in a few days after good sunshine do the pressurization test.

 

[Arbee]

Given our 306 has been bone dry since I last updated this thread (and through several big downpours), I thought I'd update in case anyone is interested. it must have been simply my over-enthusiastic hosing over the sliding hatch area that caused water to be forced past the barrier and gradually working its way down to the bilge (still not sure of the full path however). Although normally cautious of hosing the sliding hatch, I did eventually recall that I "let loose" one day and it must have taken several days for the water to slowly work its way down to the bilge. Hopefully, as a one-off (and we've had some hot weather since), there is no permanent water damage behind the head liner that will haunt me one day. I must take the sliding hatch apart one day and figure out what path the water takes.