The article makes no mention USCAVs (undersea combat autonomous vessels), the UCAV’s of the sea.
If you think that manned *flight* is being challenged by remote control, you should “sea” what’s going on underwater...
The huge volume of air and space needed for the crew, the air recycling, food, sewage, and other necessities of a manned submarine are a huge impediment.
An "Autonomous Undewater Vehicle" or "Unmanned Undewater Vehicle" can be much more efficient.
See also Unmanned Gliders, which navigate almost silently.
http://www.onr.navy.mil/media/extra/fact_sheets/advanced_underwater_glider.pdf