Find the Water Chip

Find the Water Chip is a Fallout quest.

This is the first official quest, go and retrieve a new water chip for Vault 13. Although there is a time limit for this quest (150 days), there are many other side quests to do. However, this guide is written on the basis that the player will ignore the side quests and attempt to retrieve the water chip as fast as possible.

Vault 15

 * Exit Vault 13 cave entrance.
 * Travel to Shady Sands, which is located on path to Vault 15.
 * Acquire some rope.
 * Pickpocketed off of Seth.
 * Found in bookshelves, or traders.
 * Enter Vault 15 and use the rope on the broken elevator shaft.
 * On the second level another rope can be found in the locker in a side room on the way to the second broken elevator shaft.
 * Descend to level 3, enter the area were the command center should be, earn experience for discovering the destroyed command center.

The Hub

 * Travel to the Water Merchants, and ask them to send water to Vault 13.

Necropolis

 * Travel to the Necropolis and enter the sewers.
 * Travel to Watershed area.
 * Either convince Harry you are an highly advanced robot with a high speech skill, or attempt to sneak past.
 * Speak to the imprisoned ghoul, and then enter the vault through the cell (with an actual door) located next to the ghoul's cell.
 * Travel to the third floor via the elevator and take the water chip from the command center.
 * Return to Vault 13 and give the chip to the Overseer Jacoren.

Detailed Walkthrough
As soon as The Vault Dweller leaves the vault, the map has the location of Vault 15 provided, where there will presumably be a water chip. Stop off in Shady Sands, which is on the way to Vault 15 anyway. Get some rope, either on Seth, bookshelves, or from traders. Find the location of The Hub and Junktown from Ian, who resides in a house to the left of the entrance.

With rope in tow, fast travel to the vault. The vault entrance is hidden by the uninhabited shack. Open the hatch and enter the cave system below. Follow the caves, which are inhabited by a few Giant Rats. Enter through the destroyed door, and find the elevator. Use the rope on the elevator shaft to descend to the next level. There is only one object of interest on this level: a locker which contains some more rope. Get this rope, then head to the second elevator shaft and descend to the final level of the vault.

On this level there are a few Mole Rats and more Giant Rats, take them out and head to the bottom right hand corner of the level. Finding the Command Center will reward 500 XP. Unfortunately, the command center is caved in. The water chip is not here.

Travel to the Hub, and head south and enter the Water Merchants area. Go into the large building and find the office where there are a number of people crowded around a desk. Behind the desk is the 'master water merchant'. Talk to her, not only will she be able to supply the vault with water for an extra 100 days if time is running out, she can also give the location of Necropolis. Whenever she mentions water or Necropolis, press her about the subject and she will eventually give Necropolis's location and say that for some reason, they don't need water delivered there. Necropolis has a water chip so head on over there.

Once in Necropolis, go to the Watershed area, find a building with some Super Mutants and an imprisoned ghoul. In order to have run of the location without combat, you can either try to convince the Super Mutant leader Harry that your character is a highly advanced robot with a high Speech skill, or you can attempt to sneak by him and his Super Mutants. Then proceed to free the Ghoul prisoner and he will identify the entrance to Vault 12 in the adjacent cell.

Get the chip and return to Vault 13 and give it to the Overseer. Job done.

Once you have handed the Water Chip back to the Overseer, he will give you the next 2 quests Destroy the Mutant leader and Destroy the Source of the Mutants.

Reward

 * 7500 XP
 * no time limit.