TDU-Launched Comms Buoy
I found a couple of neat articles (here and here) on a new system that's supposed to start testing next year. Part of the "Comms at Speed and Depth" (CSD) Program, it's described as a communications buoy that links a submarine to the Global Information Grid through a miles-long tether; the 40 inch long buoy is launched from the TDU, then floats near the surface while the submarine continues operating normally, in constant communications with bothersome bigwigs. Other than concerns about running at speed and depth with the TDU Muzzle Ball Valve open, it sounds like a promising concept to me.