How can a deck hose on a boat work without power??

Question

I was told that some boats have some sort of plug at the bottom that a hose can be fitted to. When opened, the weight of the boat pushing down causes water to jet up through the hose with enough pressure to hose the deck...

Can this really work on its own? Or does it need some sort of motor/pump?

Answer 1

That only works in cartoons.  It takes an external power source to lift water higher than the waterline.