You will require a diving mask to swim underwater for a long time. Here's where you can get one.
In Horizon Forbidden West, Aloy can now swim underwater which means more secrets can be discovered. But as it is in many games, there’s a time limit for how long you can breathe underwater and the meter will display how much time you have left. To swim underwater for longer, you will require a diving mask and once you unlock it, you can dive to extreme depths without worries.
Thankfully, there’s no special button you need to remember to use to put the Diving Mask on Aloy’s face. It will happen automatically when she dives into the water so you can swim for as long as you like. Plus, the mask will work for any other mission after it’s unlocked.
Hopefully, that solves your query about how to breathe and swim underwater for longer in Horizon Forbidden West. Don’t forget to check out our guide on how to unlock the Sunwing flying mount in this game as well.