>>514891954
They also revealed for the first time a 2005 successful mini-sub landing and departure, possibly corroborated by DPRK’s reporting(in Aug 2006, but not necessarily that it was found then, just reported on) their finding a UUV of American origin. It’s usually controlled via fiber optic link, returning to a pre-set rendezvous point in the event communications are severed. Who knows why it was left behind- the timing leads credence to at least part of the NYT article.
http://www.hisutton.com/Captured-UUV-in-Pyongyang-North-Korea.html
https://www.forbes.com/sites/hisutton/2020/03/11/mystery-solved-the-submarine-spy-drone-captured-by-north-korea/