The Water Tablet is a flat, palm-sized rectangular piece of wood, stone, or metal painted a deep blue color. The two vertices at the top of the piece are ground so that each is a smaller angle measured at about 135°, instead of 90°; the bottom corners of the tablet are kept as square angles. The bottom edge of the artifact is cut into 3 grooves of different lengths, seemingly possessing a certain significance to its power. The Water Tablet's surface is lined with arcane, perpendicular lines and miniature, illegible inscriptions. All these traits combined together give the item an appearance similar to that of other Moon Tribe artifacts.
When equipped, the Water Tablet allows Amaterasu to move on the surface of water bodies, therefore enabling her to traverse large distances on water quickly while not drowning. This also allows her to move upstream, against the flow of a current that would normally push a lily pad downstream or destroy it completely; this ability is needed in finding a certain clover at Agata Forest or acquiring Stray Bead #40. Also, if Amaterasu equips the Water Tablet while she has been swimming, then she will immediately be pushed to the water's surface when exiting the Fan Menu.
After the defeat of Ninetails, the Water Tablet could be purchased from the Emperor for 100 Demon Fangs. If not bought then, the Holy Artifact could be obtained from Marco aboard the Ark of Yamato in the end of Amaterasu's journey, though if acquired then, the item would be useless, because there is no need to cross a body of water at that point in the storyline, except for countering the attack of Orochi's water head.
- Waka is shown to have the power to walk on water. It is never stated if he uses a Water Tablet to achieve this.
- Due to this item's similarities to the Fire Tablet, it is likely for this item to be also constructed by the Moon Tribe.
- It does not allow Amaterasu to enter the Dragon Palace via the whirlpool: she will simply be pulled in and returned to shore as if she had entered the whirlpool while swimming, with Issun reacting with his normal message. This is probably a design oversight, since there is no real reason to deny access to the Dragon Palace by the time the Water Tablet is available.