TB wrote:
I will be installing A through-hull for the overboard discharge soon. I
would like it to be as far forward as possible.

It should be aft of the head intake. When the discharge is forward of
the intake, waste can be pumped back in and recirculated through the toilet.

If you're installing it to flush the directly overboard at sea, it
should be within 6' of the toilet...because that's as far as bowl
contents will move in the amount of time 99.999% of people will spend
flushing.

If you're installing it to dump the tank, it's necessary to put it
within the pump specifications--how far it can pull and push waste
depending on bends etc. If you're installing an electric macerator pump,
it's especially important that the pump be close enough to the tank to
prime quickly, or the impeller will "fry"...and still be close enough to
the thru-hull to push the waste overboard.

I presume that having it
face forward at all would not be a good idea as water will be forced
into it when underway.

It would, but the thru-hull shouldn't even be open while underway except
when the toilet is actually in use...which is another consideration: in
order for it to be possible to keep it closed except when actually in
us, it should be readily accessible in the head. But why would you want
to "shoot" waste forward anyway??? It should go aft.

Is the depth of the discharge a consideration
i.e. just under the waterline or 2 feet underthe waterline.

Since the waterline on a sailboat changes depending on degree of heel,
it should be low enough on the hull to be at least a foot under water at
any angle of heel. And there should be a vented loop in it that's at
least 8-12" ABOVE the waterline at any angle of heel.

Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/html/get_ri...oat_odors.html