I too am installing a bilge pump in our
, in the popular "starboard under the cooler" location.
I do not want to create a new through-hull, even though it would be above the water-line.
So I want to use an in-line "T" or "Y" connector into either the:
1) head sink drain-line.
2) stern engine motor well drain-line.
I want to avoid any backflow into the bilge (either salt from healing or fresh from the sink), or backflow into the sink when the pump is running.
I have seen a few posts about "check valves" etc. Any advice, or do's and dont's on this?