It's like something from an expedition to an alien world: "scuba diver attempts to swim in Argentina's Nahuel Huapi Lake, which has been recently covered in ash after the eruption of the Puyehue Volcano in nearby Chile."
The eruption was in 2011. Here's higher-quality video (with loudly clipping wind noise) of the undulating blanket of ash atop the waves:
Here's a clip of ash and pumice washing ashore:
Here's what Nahuel Huapi normally looks like:
Here's a lake covered in dogs:
Good morning 7 pic.twitter.com/OznDTPE4Eq
— Rabih Alameddine (@rabihalameddine) February 18, 2018