How does a bong work?
It's actually pretty simple, you light the slide piece holding
whatever it is you are smoking, it goes down a tube on the bong and
goes underwater, the sucking motion is pulling air through the
slide and down the tube. The air at the bottom of the water is
trapped, and the only place it has to go is up through the bong and
into your mouth, this is why a bong bubbles, I hope I explained
this well enough.