Is VLF the ONLY way to transmit and receive? I don't need to use the Wiki for that one. Just take my word as someone who's deployed on 4 subs, working in Radio/ESM that subs can transmit.
No, obviously not, but I guess it's one of the only ways of transmitting under water (20+ meters) without using the buoy radio array or whatever you call the thing attached to the cable.