Conference unifix::sailing

    You indicated that you take on water on a port tack and the thru-hull
    is also 8" above the water line on the port side.  On a port tack
    wouldn't the thru-hull be much higher out of the water?  On a port tack
    the starboard side would be down.  So much for the nits.
    
    A solution, if its possible on your boat, would be to route the hose
    high on the starboard side before going over to the port thru-hull.  On
    a port tack the thru-hull would be high out of the water.  On a
    starboard tack the hose would be much higher than the water being on
    the other side (starboard) side of the boat.
    
    On a previous boat I had a problem taking on water through the cockpit
    drains when heeled over hard.  I fixed it by crossing the drain hoses,
    port drain to starboard exit etc.
    
    I would not put a seacock on the bilge thru-hull.  You would be
    unprotected if you left it shut which would probably burn out the pump.
    
    Good luck, water problems are no fun.
    
    Chuck

    re .1
    Thanks for the correction on the tack.
    
    The bilge pump is manual on/off.
    
    How about a check valve, would that do the trick?

Please see Note 275 for a discussion of bilge pump plumbing. Check 
valves are not a good idea -- they restrict flow considerably and they 
have been known to fail. Another solution to the problem would be 
better.

    My point in .1 is not to have the high loop in the hose on the same
    side of the boat that has the exit thru-hull.  On opposite sides it
    will put either the exit or the hose loop higher than the outside water
    no matter which tack you are on.
    
    Is this possible?
    
    Chuck
    
    

    This is possible and is worth a try.
    
    Thanks.

    re. .1 
    
    
    I believe that every hole in the hull should have a seacock 
    
    As far as check valves are concerned, I have one on my bilge pump and I
    am not aware that it causes any problem.  It certainly does solve the
    main problem of unwanted water on (in my case) a STDB tack.

    I guess I am a little old fashioned when it comes to bilge
    pumps.........I think that Soddes Law of the Sea might read something
    like this on the subject . Seacocks if fitted to a Bilge pump outlet
    will always be off and buried under an a mound of assorted kit when the
    pump is required, one way valve will stick after a minute or two of
    bilge pump operation due to the nature of nasty things of uncertain
    origin that often get lifted from the strum box. 8^)
    
    I go for the solution suggested earlier ie intelligent piping with a
    big swan neck built in and the bigger piping the better.
    
    Pete

    Pete,
    
    What is a Swan Neck?
    
    Bob

    Bo,
      Mentioned in earlier replies it is a gradual loop of the pipe taken
    to the highest point you can get it. My piping for the seacock, toilet
    , engine all have swan necks with double clips on where the pipe goes
    through the hull.
              --
            -   -
          -       - 
        -           --------
      -
    -- 
    
    ie just a "salty" name for a loop in the pipe. The earlier noter who
    suggested if you can arrange the piping to be swan necked on the other
    side to the outlet has I believe the solution you require. I do however
    believe that bilge outlets should be as close to the toe rail as
    possible for practical reasons ie more time to pump .......
    
    Pete

    I know from partical experience that you want the piping as short as
    possible, since pipe itself can hold a lot of water as I pointed out in
    275.6. The longer the pipe the more water you will have to pump out by 
    hand/sponge/bail, because you never can pump out the volume of water
    contained by the pipe from its intake upto the highest point. (You run
    out of water at the intake to push water up the pipe, and most bilge
    pumps can not pump enough air to clean the line.)
    
    Another problem with the swan necks (high loops) is that you are
    increasing your water head and therefore decreasing the flowrate of
    your bilge pump. 
    
    This is why the suggestion of putting the loop on the opposite side as
    the outlet doesn't excite me either.
    
    I don't know if there is a good answer, maybe a flap valve on the exit
    through hull (but then you would have increased back pressure, and
    reduced flow).
    
    Maybe you could never put the rail in the water. 8-) 8-)
    
    /jim

    re .6  seacocks on all thru-hulls
    
    I would agree that all thru-hulls under the water line should have
    seacocks.  The bilge thru-hull should exit much higher than the water
    line as well as the cockpit drains.  I would not put seacocks on the
    bilge or cockpit exits.  When you are away from the boat you need these
    functioning.
    
    re .10  decreased flow caused by loop height
    
    I would agree that the pump must have the capability to overcome the
    height of the loop.  Most of the pumps on the market should handle the
    4 or 5 feet necessary.  My intuition says that once the pumped water
    reaches the highest point a siphoning effect would take over as the
    water falls to the exit and the flow rate would not be greatly
    decreased.  Hose diameter and pump capacity will have the greatest
    impact and these two need to be matched so the hose can meet or exceed
    the flow rate of the pump.
    
    Chuck
    
    

    For what its worth.
    
    On my 30 foot Pearson (1967), I have a Rule 800 pump located in
    the bottom of the full keel, right below the front end of the engine.
    The hose travels aft about 18 inches and then climbs up out of the
    keel, goes along the bottom of the boat (beneath the cockpit sole)
    and exits the boat through a moulded in fitting. The opening for
    the bilge hose is under the counter, right at the aft end of the
    boat. This places the openong about one foot above the water line
    and only two inches of the center line of the boat.
    
    Heeling does not seem to make any difference, and in most cases,
    the opening never goes under water. I have never had a breaking
    sea over take me (yet). There is no goose neck in the line.
    

    I agree with 0.12. When I installed my (manual) pump, I put the
    thru-hull on the transom, just above the exhaust outlet. The pump
    itself is just under the starboard cockpit seat so it is higher than
    the through hull. You may want to consider plugging up the thru-hull on
    the side of the boat and exiting through the transom.
    
    P.S. Don't forget the loop (preferably high and amidships) just before
    the thru-hull.
    
    John

    right.  Every boat I've owned has the bilge pump exit in the transom. 
    The pumping is done from the cockpit.  Racing rules require a pump down
    below, too.  We Y-valve that pump to the same exit hose, but for
    simplicity never use it.  In fact our new boat has the bilge pump exit
    into the cockpit itself near the back.  Ofcourse, it's an open transom
    design, but if the pump exit ever gets under water for any length of
    time I'll have much bigger problems to think about!
    
    Dave

re .14:

>>> Every boat I've owned has the bilge pump exit in the transom. 
>>> The pumping is done from the cockpit.  Racing rules require a pump down
>>> below, too.  We Y-valve that pump to the same exit hose, but for
>>> simplicity never use it.  

Is using a Y-valve a good idea here? I would think that there might well 
be a disastrous time when being able to use BOTH pumps simultaneously 
might mean staying afloat instead of sinking. 'Twould seem better to me
to have separate outlet hose and through-hull for each pump. 

> re .14:

> >>> Every boat I've owned has the bilge pump exit in the transom. 
> >>> The pumping is done from the cockpit.  Racing rules require a pump down
> >>> below, too.  We Y-valve that pump to the same exit hose, but for
> >>> simplicity never use it.  

> Is using a Y-valve a good idea here? I would think that there might well 
> be a disastrous time when being able to use BOTH pumps simultaneously 
> might mean staying afloat instead of sinking. 'Twould seem better to me
> to have separate outlet hose and through-hull for each pump. 

    Do you mean Y-valve, or just a Y shaped join. The latter is what we have
    in the Scampi I sail on, both pumps discharging through the same thru-hull
    fitting. Works fine with no water going the wrong way. This was done 
    because our cockpit mounted pump discharged into the cockpit, which was 
    not an open transom design. This contravened ORC safety regs, so we
    have changed it. Both pumps can be used simultaneously.
    
    Chris
    

    SORRY!  I did mean a Y connection, NOT Y valve.  You can use both pumps
    at the same time.  However, the interior pumps have been located far
    enough from the companionway that I would not want to be the one below
    doing the pumping in such an emergency!
    
    Once the water intake hose for our diesel came off while motoring and
    filled a good six inches of the cabin with water.  When discovered we
    reconnected the hose to the engine, disconnected the hose from the
    seacock and put the hose into the bilge.  Turned the engine back on and
    let the motor do most of the pumping for us.  This was on Fat Tuesday
    which had a marinized 80 hp Isuzu tractor engine, so it used a lot of
    water.  Smaller engines would take all day.  We did rig up a strainer
    to the hose to keep bilge goodies out of the engine.
    
    Dave