Mystery Leaks

Feb 15, 2009
18
Oday 28 Manhasset Bay, LI
Everyone gets them, but I'm wondering if this is specific to old Morgan 34s, so let me post my issue and present my hypothesis...

Over the years, when we visit our boat, sometimes after a several week absence during the boating season, we'll find water in what I call the upper bilge where the stuffing box for the centerboard is located. It's fresh water, so no the stuffing box isn't leaking. Sometimes it's dry as a bone. Adding to the mystery, just this last season I spotted another pool of water on several occasions along the port salon bookshelf, turning some of our stored literature to sponges.

Owners of the M34 are likely aware of the curious system Charlie built into the deck/hull joint, designed I assume to catch water that might make its way through the joint. It's essentially a gutter system that funnels water back into the main bilge through a series of troughs and tubes. It is as I say, a curious system.

After a heavy storm, sometimes I find water, sometimes not. What's going on? Here's my theory. I think that the two dorades flanking the mast, which are there to offer airflow into the head and main cabin, can be overcome in a hard driving rain by the amount of water entering the dorades, which are naturally facing into the wind while the boat points on her mooring. There are drain holes for evacuating that water, and raised tubes that I presume are there to handle the buildup while the tiny holes do their job, but what if a windy rainstorm overwhelms them? The water level might, it seems to me, rise up, overflow those tubes and take the easiest path into the boat via the gap between the hull and headliner. If so, one might see water make its way into the "upper bilge" and possibly overrun that port side "gutter". The boat could also experience a hard rain with no wind, and as a result have no water collect at all. I realize there are other means for water ingress, but those I've contemplated just don't fit the symptoms. For instance, I always turn our bow dorade aft before leaving the boat, since that orifice is an unobstructed straight shot down into the anchor locker and beyond. I don't know how else I'd be getting these on again/off again results after lots of rain.

Thoughts?
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
24,454
CAL 35 Cruiser #21 moored EVERETT WA
Water leaking into a boat can be a tricky experience. I swear I have seen water wick uphill against gravity to get into a certain location in the boat.

My general suspects are hardware that in on the deck. Over time the screws/bolts holding the hardware to the deck eventually leak. This is just about any hardware. Jib sheet tracks, deck hand grips, mast bases, ports, stanchions, winches, etc. you name the hardware it has contributed to water leaking into a boat.
 
Jan 1, 2006
7,934
Slickcraft 26 Sailfish
Those Dorade vents could well be the problem. Remember in a storm there are frequent violent wind shifts which could overwhelm any effort to orient the dorades in any position. And the vents can fill with water especially if the drains are in the least way compromised.
Some time with a hose on a clear day may teach you a lot.
You should probably seal the tube that penetrates the deck so that water that runs around the tube doesn't soak into the core. If water just ran through and ended up in the bilge that wouldn't be the worst case. Presumably a auto pump could de-water the bilge. But if it enters the core big problems could result.
If sailing offshore the Dorade vents would normally be closed.
 
Feb 15, 2009
18
Oday 28 Manhasset Bay, LI
I'm with you on water being a clever creature, John. And old boats seem to be in collusion with the medium. I've been shamefully negligent when it comes to painful, time-consuming maintenance. The thing about this is the irregularity of it. Why last week's rain and not this week's?

And yes, Andrew, I'm going to take a hard look at those dorades when I get to the boat. I just got some butyl tape for the first time and am going to try that stuff out on several sites.

On an unrelated note, Andrew, while I'm up here in New York, Deb and I fairly frequent Jensen Beach, where her mother and a sister have been for many years. So hello down there.

Thanks to the both of you. Fair winds.
Paul