Can Someone Tell us What This Is I found in a 340 Searay Sundancer Toilet System?

Maybe an IUD from an elephant?

 

I don't think it belongs anywhere in the system. It looks like some sort of mushroom flapper valve from something else. Not sure how it got there, but hey it's a boat.

 

You were smart not to touch it

 

Good eye on the needle nose @Blueone. Not that I've had one in my hand lately but, could that possibly be the flapper valve from the vacuum switch, or one that has been replaced before?

 

And we have a winner! Didn't even think of that one. But that's certainly what it looks like.

 

That looks like the valve to the tank saver. It’s a negative pressure relief valve installed in some tanks to let air in when pumping out, but otherwise contains the stink. Otherwise, your tank will “oil can” and eventually spring a leak.

 

If Dave can flip that pic over, I think I may be the first looser.

 

Looks a lot like a suction cup from one of those bathroom / shower caddy’s. Could have fallen in the toilet inadvertently and been flushed. Note the little flap on the side to break the suction free.

I suspect it used to be clear and quite a bit more pliable.

 

Agreed. Plus half of it still has a resemblance of an outward slope.

 

This. ^^^

 

Looks like there also be be part of a tortilla in there as well.