I don't know if this has happened to anyone, but yesterday the provided Melnor quick-disconnect that I use to attach the water hose to the flush intake at the back of the ski, failed! No water was going in!

Good thing I noticed it quickly!
Ok, I presume it was operator error, but I just thought I'd throw this out there.
There is a plastic ball in the middle and it is capable of blocking all water flow. It seems to depend on how far you push adapter on your flush intake. Apparently, you can actually attach it with the ball blocking water flow. Whatever.
I will not be using it anymore! I bought a quick disconnect that has a valve lever that you rotate. That way I can just look at the lever position and know whether or not the water flow is on or off. No worries!