| ||For Fallout/Fallout 2 miscellaneous item, see Water flask.|
As long as the canteen is kept in the Courier's inventory, they will take a sip from it every five minutes, restoring 15 HP and lowering Dehydration by 25 in Hardcore mode. An on-screen notification will tell the player when this happens.
There is no way to forcibly take a drink, nor does the canteen ever run out of water; the five-minute timer starts when the canteen is placed in the Courier's inventory (not when a save is loaded) and runs in the background, even while the Pip-Boy is up. Under certain circumstances, such as when sleeping or fast traveling right before the hydration level reaches the trigger point, the player can skip this trigger point and become dehydrated.
Originally, the only way to acquire this item was by redeeming the code that came with the pre-order exclusive Classic Pack. It can now also be acquired by purchasing the add-on Courier's Stash or by having the Fallout: New Vegas Ultimate Edition, which includes all add-ons.
- Aesthetically, the canteen appears as a hip flask surrounded in a fabric coating featuring a "13" in distinctive vault jumpsuit coloring.
- This canteen is from the vault that the main protagonist of Fallout, the Vault Dweller, came from.
- This canteen is a great item to effortlessly stave off dehydration during Hardcore mode, especially because dehydration increases faster than either hunger or sleep deprivation. The canteen is not enough to single-handedly save you from dehydration, however, and should always be supplemented with other water sources.
- The font used for the "13" is different from the font used in Fallout and Fallout 2.
- There is no special animation associated with drinking from the canteen; as with other First Aid items, the screen notice, slight HP increase, and H2O meter drop are the only indications it is working. It can be seen in use while the Courier is attacking an enemy in V.A.T.S., or while the Courier is underwater.
- If the timing is right, the on-screen notice will appear during the game's ending. This also applies to the ending of the add-on ending screen.