there so much water in the bilge
after a rain?
"Where's the water in the bilge coming from?"
This is becoming a very frequently asked question. However, it
is not so simple a question to answer. For the keel stepped mast
boats, there are a few more questions to be asked--fresh water? or
salt? and in which compartments of the bilge? I have a
dry bilge when the boat is in the water (Dripless Packing MAINSHEET
There are four compartments to the bilge. A small one (#1)
just forward of the mast (with only 1 keel bolt); #2 just aft of the
mast (with 1 pair of keel bolts); a large section #3 containing the
manual bilge hose/electric bilge pump (2 pair of keel
bolts); and an aft section #4 (with 2 keel bolts). On Apache, hull
#788, there is a 1/2 to 5/8 inch drain hole from the forward bilge
under the keel footing to compartment #2 and another drain hole
(same size) to #3 compartment. Then a much larger hole (i.e.,
3 inches) to accommodate bilge pump hoses between the aft two
compartments. This larger hole is up from the
bilge floor a few inches so any water will tend to accumulate. Rain
water will wick down the spinnaker halyard into the halyard
exit near the top of the mast and then into the center of the mast.
This rain will exit the mast base and accumulate in compartments #1
and #2 and even overflow into #3 if there is a lot of rain.
Thunderstorm type rain with high
winds may only accumulate little to no rain. I've found the
worst is a long steady drizzle. If you
don't have a spinnaker, tape over the exit. Ralph Caruso
[below] mentions my flap if you have a spinnaker
halyard, but it's far from being perfected.Another source of rain
water is obviously the mast boot, but in particular a poorly caulked
mainsail track at the top of the mast boot. Water will
empty into #2 and overflow into compartments #1 and #3.
- No rain but fresh water in compartment #3? Check
the starboard water tank outlet, cap and vent fittings.
Fresh water in #4? Check hot water heater, all
of the hose connections, under the sink as well as the shower
sump and sink connections in the head compartment.
- Salt water (again with dripless packing) only in
compartment #4? Check packing gland, raw
water hose intake/strainer in head, raw water connections at
engine pump and heat exchanger, as well as all through hulls for
- Salt water only in compartment #3? If
you've been sailing on a port tack or a following sea, water
will siphon from the separate electric bilge pump exit on the
transom back into the bilge. I believe all the walk
through transom boats have the electric bilge drain "T"ed
into the manual drain which is high enough to prevent back
siphoning. If this bothers you, install a one-way valve in
the electric bilge pump hose. If I find salt water in only
#1, #2, and possibly overflowing into #3, I look at the depth
and knot log transducer fittings which are located under the
The C34s with a deck stepped mast shouldn't have the rain water
problem but make the appropriate checks if you find either fresh or
salt water in the bilge. I have had one extraordinary storm
that blew horizontal rain in from the stern. It blew water in
through the slots and around the hatch boards. Fresh water was
found in #4, but again that was extraordinary. I'm a firm believer
in a dry bilge, if for no other reason than that it helps you find
water leaks. If you are a believer in a dripping packing
gland, I'd strongly recommend you purchase a counter (12 volt
Radio Shack) and wire it to your electric bilge pump. Every time the
pump cycles, it will register. An increase in the number of cycles
in the same period of time will alert you to a leak. Also note the
information in FAQ Winterization (Ron
Hill, Apache, #788)
In my 34' #247, I always had lots of water after a
moderate rain. After 2 years of reseating most everything, I
found that my fuel cap had never been caulked. I was and I
still am amazed at how much water came in from that one source.
If there is water in your head counter top after a rain, this would
also explain that. In addition, if the prevailing winds are
directly aft when it rains, a fair amount of water comes in the
exhaust blower vents. I have also reseated the chain plates
and one port. but the fuel cap was 90% of the water.
I could never understand how 1" of rain water would put at
least that much in the bilge. But the fuel cap was acting like
a wick (David Aucella).
Lately, when it has been raining, I've been
checking the bilge and noticed that I have some water which is
coming into the bilge at the bottom of the mast from the inside of
the mast. I'm sure this is not water that is coming in around
the boot, because I have taken a dry paper towel and run it along
the outside of the mast to make sure that it was dry. I've
been told by a local boat repair person that it is just rain that is
blowing in through the holes where the halyards run through the
mast.Do you know of any way of solving this so I can have a dry
bilge, or if there is any retrofits offered by Catalina to cover the
holes? Or, if it is something other than this? ( email@example.com)
I had a similar problem on my 1990 C34 Mast step.
First the drain hole from the bilge in front of the mast step to the
portion after the mast step (under the Mast Step) was not there. I
had used a drill to "poke around until I found the hole that
had been covered over during manufacturer with excess filler. I
never thought much about it and filled the holes temporarily with
Polysulfide caulk. Later I decided to remove the caulk and fill the
holes (about 4 each 3/16" holes) with epoxy. When I drilled out
the epoxy, I found a lot of water began coming out of the wooden
mast step. I kept sopping up the bilge and letting it drain. I
placed a heater aft of the mast and let it blow at 500 watts for
about 24 hours and the drainage stopped. I then sealed the holes
with West System thinking maybe the water came in from the bilge
holes I had filled. I would bet the mast step is wet again, but
currently I have the Mast pulled and plan on removing the metal Mast
step bracket to gain access through the step top side. I will then
drill out the bottom again and let it drain again. My thoughts were
that I would drill out the current holes for the metal bracket with
a over size bit or hole saw the fill them with West System including
Colloidal Silica (406) or High Density filler (404) then re-tap
holes for the lag screws to hold the metal bracket. Since I have the
mast down I am looking at the top to figure out where the water
enters the mast. On my mast the Signet Wind Instruments are mounted
with a hole drilled in the top. It is not caulked so I will be
filling it with polysulfide. There is a top plate on the mast so I
can't see how water
can get in other than through this hole (Gerry Misener).
Ron Hill had an idea to put a small
rubber flap over the opening on the front of the mast where the
spinnaker halyard exits. Evidently, it faces upward, and may
be a major source of the water. The top of the mast itself has
a cover ( I didn't know this till I went up and looked for myself).
One source of water through the mast you may not
have considered is condensation. I finally traced via process of
elimination that as the most probable cause of periodic water coming
from the mast of our '91C34. Down here in Texas we keep the boat in
the water year round with heat on inside the boat during the winter.
I finally figured it out after a norther blew through and pushed all
the nice balmy moist air out of the area without making any rain,
and I had lots of water exiting the mast. The mast offers an amazing
total surface area if you condense water inside it over its full
length and run it out a hole at the bottom. If it trickles out along
the wiring bundle onto the cabin sole, it looks like a LOT of water.
I had to make sure the wiring harness drips went into the bilge an
not onto the sole (John Nixon).
Fine, but I'm still getting water in the
bilge even if it's not raining and there's low humidity!
I hate to make this suggestion but have you tasted
the water? It may be from your water system. If its from
a tank fitting before the water pump you wouldn't have any pump
cycling, although you'd be filling your tank more often than
otherwise (Bob Greenhaus).
I agree with Bob in that you should check your fresh
water system. I had a small leak in my aft fresh water hose
and it took me a while to track it down. Also, your hot
water tank may be dripping water from the safety valve if it gets
too hot when you are connected to shore power. All that
being said here is how I tracked down the problem on my 34. I
connected a "Y" valve at the shower sump and led a hose
(under the sole) to
the bilge. This allowed me to easily vacuum up the water that
the bilge pump would leave behind. Now, with a dry bilge this
allowed me to closely study where the water was coming from.
If you are getting 2 to 3 inches in 24 hours you should be able to
find it quickly. I had a leak at the rudder tube that I glassed over
and the stuffing box needed adjustment. Now by bilge is dry as
a bone. To keep it that way I blocked up the drain hole in the
aft horizontal stringer. Now water that leaks from the
stuffing box collects there, it's easy for me to vacuum up
with my shower sump pump. There was a time when I thought a
dry bilge was impossible, but once you dry it out it will be easy to
find the culprit. Note: you must had dry the bilge after
vacuuming. It take forever for the water to evaporate in the
bilge (David Aucella).
I used a Y-valve to T into the fresh water line just
before the 12 V pump so I could get water from a foot pump in case
of a failure. I purchased the garden hose Y-valve,
barbed fittings and hose at West Marine. I'm sure that this
same Y would work in the shower sump line. Another thought
would be to T into the raw water intake for the engine cooling.
This could have a two-fold purpose. First, it would be
easy to rewinterize after a winter sail and secondly could also act
as a backup bilge pump in case you ran into a big BIG leak.
The Y-valves and fittings I'm talking about are for 1/2 to 3/4 inch
hose (Ron Hill)
Important: The opinions expressed here are
those of the individual contributors to this page, and not those of
the Catalina 34 National Association or Catalina Yachts, Inc.
Additionally, this material has not been reviewed by Catalina
Yachts, Inc. for technical accuracy. This page's maintainer cannot
guarantee the accuracy of this information or the desirability of
suggested modifications or upgrades. Please obtain assistance from a
competent marine mechanic or boatyard prior to making any
significant modifications to your vessel.