Appreciate all the advice - the line is a continuous gradual run to the exit point. I will make a better seal at the pump ,it is difficult to see if I am leaking water there -possibly losing pressure to have water exit the boat. To sum up-the pump pushes water through itself exiting at the end of pump nipple -once attached to a unrestricted ,continuous and straight run hose to the exit point of the boat, that's when the impeller spins creating a current in the bilge water and not pushing water though the line and out of the boat. What seems to be an easy process of elimination in theory is more of a brain tease-Thank you for video on air lock-will continue to work on solving the mystery-Regards Andy