I see some major defects with the system you've discribed/drawn.
First, that's fine if your sitting in port but what happens when your transom rises up over the crest of a wave and slams back down or like on many vessels with positive bouyancy aft ends. Or, where the transom may over hang as much as 3 ft., like mine. http://cruisersforum.com/photopost/...20TRIX1-med.JPG
(you are correct – this idea would only work with a center cockpit
, where the cockpit through hulls are in the center of the boat, down deep. Another option is to feed the aft cockpit drains via flex hose toward the deep bilge
, into 2 manifilds and plug
the existing holes aft. This is way more work than anyone would want to do but I still like the 2 hole idea. )
Second, it's not really a good design to have the cockpit drains below the waterline, as you can see by some of the first posts on this survey
(I probably drew it wrong. I agree that the cockpit drains need to be above the waterline, or at least should be there)
I agree with the manifold design for intakes but prefer overboard
discharge above the waterline providing the sinks and such are high enough for drainage. There's less back pressure and less chance of another source of sinking.
(agreed. Another setup I like is sink drains feeding into the deep bilge to a container and the water then fed overboard by a bilge pump. Hair and slime build up which means it needs lots of maintenance
, but it lessens the chance if water incursion)
As for the Groco setup, the problem I see there is it has a large thruhull, then it reduces it down before the manifold (top of the elbow). What good does that do to have a large thruhull? The manifold should be as large as the thruhull and then the outlets reduced.
(agreed. If the engine
is drawing off the manifold there can be no restrictions for the water it needs and the pipe feeding the manifold would need to be quite large)
So far, the lack of maintenance and good common sence seems to be the main source of sinking vessels.
(agreed. I recall
41’ owner saying that there were 19 holes in the hull
below the waterline. Nineteen is a big number! i first heard of the 2 hole idea in an email
from a lake Michigan sailor. He went so far as to say that he lowers the depth sounder
down one of the cockpit drain fittings, on a stainless rod, and plugs the cable into a cockpit electrical
fitting. He has 2 large pipes feeding 2 large manifolds, and no other holes. nada!! When he leaves the boat he religiously turns the through hull
valves off thereby guaranteeing the boat can’t sink…well…..nearly impossible to sink…. By his method he also guarantees that the vales get regular exercise. All too often you hear about someone doing through hull valve maintenance and they say that the valve is frozen. A frozen valve is a scary thing! I would rather have 2 holes than 19 any day, but getting there with a factory boat would take a lot of time and $$$.)