how is the communication done from it?
VLF (very low frequency) radio, ELF (extremely low frequency) and burst transmission.
Submarine
Military submarines use several systems to communicate with distant command centers or other ships. One is VLF (very low frequency) radio, which can reach a submarine either on the surface or submerged to a fairly shallow depth, usually less than . ELF (extremely low frequency) can reach a submarine at greater depths, but has a very low bandwidth and is generally used to call a submerged sub to a shallower depth where VLF signals can reach. A submarine also has the option of floating a long, buoyant wire antenna to a shallower depth, allowing VLF transmissions by a deeply submerged boat.

By extending a radio mast, a submarine can also use a "burst transmission" technique. 
when was the last year they made silver nickels UNANSWERABLE who is jefferson nickel? The Jefferson nickel has been the five-cent coin struck by the United States Mint since 1938. what is the cent's design? The 1987 modification saw the sharpening of Jefferson's hair and the details of Monticello. was there any redesigning of the front side of the coin? Yes, the design for the nickel debuting in 2006 was designed by Franki. what change did the wwii bring to this minting? With the entry of the United States into World War II, nickel became a critical war material, and the Mint sought to reduce its use of the metal. how did the war affect asia? The Kuomintang (KMT) party in China launched a unification campaign against regional warlords and nominally unified China. who were the allies that gained momentum? United States, Australia, New Zealand and Pacific Islander forces. were there any use of high tech weapon in the war? Yes, guided missiles, aircraft carriers and submarines. what is the last mentioned one? A submarine (or sub) is a watercraft capable of independent operation underwater. which country built it? UNANSWERABLE what types of sensors are used in it? Modern military submarines rely almost entirely on a suite of passive and active sonars to locate targets.
wiki:19655194
Submarine [SEP] Communication
Military submarines use several systems to communicate with distant command centers or other ships. One is VLF (very low frequency) radio, which can reach a submarine either on the surface or submerged to a fairly shallow depth, usually less than . ELF (extremely low frequency) can reach a submarine at greater depths, but has a very low bandwidth and is generally used to call a submerged sub to a shallower depth where VLF signals can reach. A submarine also has the option of floating a long, buoyant wire antenna to a shallower depth, allowing VLF transmissions by a deeply submerged boat.