Waterfall bong

This can also be referred to as a gravity bong. See differences and clarifications.

Similar in design to the bucket bong is the waterfall bong. A waterfall bong usually consists of a plastic bottle with a hole punched at the bottom and a removable bottle cap with a bowl in it. The bottle cap is removed, the hole is covered by a finger, the vessel is filled with water, then while holding a flame to the bowl, the finger is removed. Gravity causes the water to flow out creating a vacuum inside the chamber and smoke begins to flow into the chamber; see the section on the bucket bong for a more detailed description of this process.