One of the dreaded "Ace" American submarines.

Sado was, in fact, sunk by USS Hake Haddo, who was with Harder at the time.

Also, Hiburi and Hayanami are missing. (Unless this is a late upload)

Eboreg said:

Sado was, in fact, sunk by USS Hake, who was with Harder at the time.

Also, Hiburi and Hayanami are missing. (Unless this is a late upload)

Indeed it is. Time stamp is on 7/2018.
But that doesn't justify missing Hiburi since she was implemented in Winter 2018 event which ended in 3/2018.

Sakazaki Freddy said:

In the end, she was sunk by Patrol Boat 22.

Thats CD-22

That's a really odd name for a submarine

Chibit said:

That's a really odd name for a submarine

As with all American WWII era subs, it's the name of a marine animal, in this case, a type of Fish.

Well... Kaiboukan no. 22 is here...

Of course, Harder's close brush with Okinami is never mentioned by the fans despite the fact that the devs (rightfully) decided to use it as inspiration for her ASW skills.