From CBS News, February 18:
U.S. military reports 1st Houthi unmanned underwater vessel in Red Sea
The U.S. military conducted five self-defense strikes in Houthi-controlled areas of Yemen on Saturday, including one against an unmanned underwater vessel, U.S. Central Command said Sunday.
Saturday's incident marked the first observed Houthi use of an unmanned underwater vessel since attacks in the Red Sea region started in October, CENTCOM said.
The military on Saturday between 3 p.m. and 8 p.m. local time also conducted self-defense strikes against three mobile anti-ship cruise missiles and an unmanned surface vessel. CENTCOM "determined they presented an imminent threat to U.S. Navy ships and merchant vessels in the region," the military said in a news release. "These actions will protect freedom of navigation and make international waters safer and more secure for U.S. Navy and merchant vessels."
The Houthis have launched a barrage of drones and anti-ship ballistic missiles in recent months, targeting dozens of ships and disrupting a crucial international shipping corridor. When they began their attacks, the Houthis said they would only shoot at ships linked to Israel....
....MUCH MORE
As China watches and collects data.