Horizon Forbidden West introduces several underwater locations that Aloy can explore. These locations usually contain a considerable number of treasures and valuable resources, while some are tied to different quests. Aloy can only explore these at a limited depth due to her rapidly declining oxygen supply. Thankfully, you’ll eventually have access to a tool that will allow Aloy to explore these areas indefinitely, without the fear of drowning.
You’ll probably come across Sunken Caverns since there’s one in the Daunt - the first explorable “open world” area in the game. These massive underwater caverns contain chests and Greensilver ores though the majority of the valuable loot is hidden deep within its bowels. Your underwater exploration is limited only by Aloy’s oxygen supply. If you fail to swim up and reach the water’s surface, Aloy will drown and you’ll restart at the entrance of the cavern or the body of water. As a convenient tip, you can use your Fast Travel Kit to “teleport” out of the cavern to safety, without drowning.
Don’t worry since Aloy will be able to get her hands on a special gear called a Diving Mask
. You’ll get the chance to craft this special gear as part of the main quest “The Sea of Sands
”. This is the main quest where you’ll have to retrieve the POSEIDON subordinate function in the ruins of Las Vegas. To start the quest, head to the marker and look for a tower ruins where there’s leaking water. If you scan it with your focus, you’ll find some friendly humans inside. Enter that tower to meet three Oseram delvers, which will update the quest.
The next step is to collect the compressed air and the necessary machine parts. The compressed air is down the elevator shaft, inside a diving bell. You should be able to reach it and swim back up without issues; just don’t swim hard and deplete your oxygen faster.
After getting the compressed air, head out of the tower then go to the marked location of the machine herd. This herd has burrowers, leaplashers, and a bellowback. You’ll get the machine parts needed for the quest regardless of the method you use to kill the machines, so do whatever you want to destroy and loot them.
Once you have recovered the machine parts, head back to the tower and report back to Molrund. After that, use the workbench there to craft the diving mask. That’s it! From hereon, you’ll be able to breathe underwater without any issues or limitations. As soon as you enter the water, Aloy will automatically wear the mask. I suggest continuing the main quest objectives until you complete it since doing so will enable a new outpost in the same location, which can serve as a convenient base for you as you explore the immediate area, as well as unlocking new sidequests for more skill points and rewards.
As mentioned above, Aloy can stay underwater indefinitely without worrying about her oxygen supply. Since she can’t fight machines underwater, always try to avoid getting detected by swimming out of the machines’ line of sight or using stealth kelps to conceal her position. You can still use her Focus to scan the area. You can also chase after fish and collect them (for Pouch Upgrades) and explore the Sunken Caverns.
Scan with your focus to highlight the fish that you can catch for your pouch upgrades
That’s our quick guide for unlocking the Diving Mask in Horizon Forbidden West. For more Horizon Forbidden West content, please check out our other dedicated guide pages for the game.