- "The most revered weapon of them all! This sword, which is rumored to be the only weapon capable of bring down the feared Dahaka, can only be obtained once the Prince has found all of the island's Upgrade Pedestals."
- —Official Booklet Description
The strongest of the seven primary weapons used by the Prince, the Water Sword can be used against Sand Creatures like the Brute and is strong enough to kill creatures like the Dahaka The Water Sword glows in the presence of water. Like the Lion Sword, the Water Sword is capable of charged attacks and can destroy fractured walls like the Scorpion Sword.
The Water Sword can only be obtained by activating all nine Upgrade Pedestals. When all nine upgrades are activated, the player will be led to a pit in the middle of the Hourglass Chamber where the Water Sword emerges. Although the Water Sword is available to players when have obtained all nine Life Upgrades, using the sword is optional.
- The in-game Mask of the Wraith cinematic was rendered with the Scorpion Sword on the Prince's back, although it is possible to already be in possession of the Water Sword.