The Waterbomb Base is most commonly known to be used in the making of a Waterbomb (obviously), but it is also used in making many other things. Sadly, the only model on this website using the Waterbomb Base is the Waterbomb, but many other models such as a variation of the iris as well as several different rabbits.
The paper here is 15cm x 15cm, single-sided origami paper. Any paper cut into the shape of a square should be usable.
Turn the paper over.
Fold the top down to meet the bottom edge. Crease then unfold.
Turn the paper 90°.
Fold the top edge down to the bottom and crease.
Lift the left flap while keeping the right side flat.
Open the flap.
Bring the creased edge to the center line.
Squash fold and crease.
Take the topmost right flap and fold it back over to the left.
Lift the right flap and bring the creased edge to the center line.
Squash fold and crease.
Take the topmost left flap and fold it back over to the right. You have completed the Waterbomb Base