PVC will never stink. It will hold up to 3-5000 impacts (or, at least, ours did) in 8-10' surf on a flat limestone shelf dry at low water
, over 3 days.
Unfortunately, my installations are spread throughout my early refit
pictures, or I'd show you (you can still meander and see them, but it's a LOT OF PICTURES!
It will behave like hose and calcify, however, if you don't do what we do, because urine and sea water make calcium in PVC, too.
Pump as you're going. Then calculate the volume of the hose, and pump about that much rinse water through (to remove all the urine), AND, then, give the same number of dry strokes, until you get burps at the other end.
The result will be that you now have a dry stack pipe, if your antisiphon valve works.
We've used ours for 8 years; I had to take both of them apart for other chores (not potty); the exit, for example, in the forward head, all the way next to the Y valve, was clean other than a very slight discoloration on the very bottom.
Pictures: Flying Pig Refit 2011-2012/Fishfinder and SSB Redo
There are two pictures which show the end of the PVC, and a couple which show the end of the through-hull nipple. The ones with the pvc show a black circle; that is the usual drain-pipe rubber coupling for drains.
I butted the pipe to the Y carefully, and it turns out that standard 1.5" hose is the same thickness of PVC, which made for a seamless butt by adding that much hose over the Y or duckbill exit. A clamp directly over that butt keeps any possible odor
from making it out, and the other ends of the coupling with clamps makes sure that if there IS a leak, it's contained.
It's easy to slide the coupling back up the pvc if you need to get to it, such as, on the other end, to rebuild
the toilet and replace the duckbill.
So, my systems have all PVC to and from toilet and Y; no possible odor
, and with the flushing
routine, also no size loss from calcification.
- but I'm convinced that our installation
will outlive us; if it can stand our wreck, it can stand any normal sailing.