My Head is in the forward middle and well below the deck I would say at
least below the bottom of the waste tank with a line at least 10' or 12'
long, I can see where a shorter line would be easier to pump, ( I have a
manual head ) I had it clog this yr., but I never had it back up, that is
unless I took the line apart when I unclogged it which I didn't with a full
tank. The tank bottom seems to be above the top of the toilet, the top of
the waste tank comes up to the top deck in the cockpit. I never had any
problem with it backing up though, the head has a pretty good check valve on
it I guess. PS this is a stock 1994 26' Chris Craft Crowne, w/ aft cabin.
good luck
"Lloyd Sumpter" wrote in message
...
On Fri, 05 Dec 2003 15:35:39 +0000, Bruce Richards wrote:

I am looking for advise on the pros and cons of locating the waste
holding tank
at an elevation slightly above the toilet (aproximately 16") verses the
same or
lower elevation. A higher elevation would enable gravity flow to empty
the
holding tank in legal waters but I am concerned about any problems it
may create
in toilet function or other unforeseen issues. I would rather ask than
create a
stink!

I'm not sure there's any great advantage to "gravity flow to empty the
tank" -
there's much to be said for a macerating pump!

Also, there are many advantages to having both inlet and outlets on the
TOP of
the tank (with a pipe going down to the bottom for the outlet), including
little
or no sewage sitting in the hoses and stinking. With this setup, you would
still
need a pump to empty it.

There's also the consideration that, if the tank is any decent size, it's
pretty
heavy when full - better have that weight low!

Lloyd Sumpter
"Far Cove" Catalina 36 - just installed 135L tank last fall.