Lake Mead Cave

The entrance to Lake Mead Cave is underwater south of the Crashed B-29. The easiest way to find it is to go to Callville Bay. There is a boat ramp that faces southeast and has a nonoperational harpoon gun that is firmly secured into the ground. The rope tied to it runs through 2 "Jamestown Slugger" bats. Follow the angle of this boat ramp and swim out into the lake that direction, pass over the bomber to get to the cave. Many shopping carts can be found scattered throughout the cave along with a few sunset sarsaparilla crates.

Layout
The cave is split into two major sections. The first section has an above-water surface that can be used to regain oxygen, and to regain health by drinking the rad-free water. The majority of the first area is underwater, and near the entrance to the second area to your left there are several crates of ammo, and two first aid kits to loot. There is a small opening low to the wall at the edge that leads to the second section.

The second section has no way to regain oxygen, so a rebreather is highly suggested. The body of a person who appears to have met an unfortunate end lies south-southwest of the large central pillar, along with a few suitcases, various loot, and a large number of (useless) poker chips. There are also various car parts scattered around and another skeleton. These skeletons are quite possible of two criminals who were chased by the police for robbing a casino.

Loot
Sunset Sarsaparilla, Lad's Life, 60 Pre-War money, Misc. containers with random loot, Ammo boxes and 2 First Aid boxes to the left of the entrance.

Appearances
appears in Fallout: New Vegas.

Bugs

 * Staying submerged underwater in this area for a long period of time using the Rebreather will return lost companions that have disappeared because of a glitch back to their own respective waiting areas.
 * When exploring the second section of the cave, a humanoid companion may attempt to follow you, but glitches and can be seen walking across the floor of the cave. ED-E may follow you through the caves as well.
 * If you tell Raul to wait near Calville Bay while in the cave, he might say that he needs help as if talking to him(Needs Confirmation if all companions do this).