Another vid from my vacation! It's the relaxing sound of waves at the beach and of the camera going underwater! (don't worry, the camera is waterproof!) Doesn't it kind of feel like you're going underwater too?!
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app