If you have a glass or metal bowl for a regular bong I can instruct on how to make a waterfall.
Take a normal Gatorade bottle and melt the lid enough to push the stem of the bong bowl through the plastic but not so melted that it doesn't harden and seal to the stem. Then melt a small hole at the bottom of the bottle. fill the bottle up with water while holding your finger over the hole. after packing your bowl, light your ganja and let your finger off the hole letting the water out. This should pull air through the bong stem filling the bottle with smoke. Unscrew the lid and enjoy your hit.