Could someone please tell me what the point is of the Black Hawk U? I think it's about space/underwater fighting, but I'm not really sure.
The U configs are mentioned in the ONN section of TRO3085. It stands for "Unusual Environment." U Configs are either optimized for underwater combat or for space combat. If a U config has liquid storage in it, then it is a space ops config (the storage used for fuel), if it has UMUs or Torpedoes it is an underwater config.
The Black Hawk U is specifically designed for space ops. The Sword helps to make landing rolls on ship hulls, the spot welder to cut into hulls.
Best,
Joel BC