My AC, shower drained to sump because they were below water line, others went overboard.

 

If everything drains to a sump and then subsequently pumped into your holding tank, then the boat has the "grey water" option. If the sump still pumps overboard, then that's just the way it is. It's a "6 of one, half dozen of the other" kind of thing. Obvioulsy, the low drains have to be pumped to the sump because of their relation to the waterline - the other ones could be done either way and the same model can have it either way. It's often dependent on the year it was built and even at which factory.

 

Some states in the US have lakes with no overboard discharges of any kind. I believe there are lakes in New Hampshire where this is the case. Your boat may have been put into service on such a lake.

 

I'd run all but the shower directly overboard, if it's feasible to do.

Some boat builders route them all to one thru hull, reducing holes in the boat.

 

The sump does pump over board but I guess because the boat was on a lake it was built to have the grey water tank option? The galley sink is what I'm concerned about because of food scraps and such. When I got the boat that drain was slow because it had accumulated lots of stuff that got nasty. I'm going to reroute that one and drain it directly over board. The only drain that's possibly lower than the water line is the shower which has been used once so far.

 

No, if it drains/pumps overboard it doesn't have the grey water option. Most lakes do not have that requirement. Lake George, in NY, is one of them that's in your neck of the woods that does, though. We'll revisit my last sentence, above, for the explanation.

But, sure, if you want to, you can divert that galley sink overboard. Or... just scrape the plates before washing them - that would be a $0 "fix"

 

I think this is an easy solution.

 

Yep that's the plan.