World wide, probably close to 2,000 subs were in use; with Germany using close to a thousand of them.
Ans 2 - During WW2 the Germans had 1,072 subs and lost 705.
The Japanese had 181 and lost 130
The Royal Navy had 218 and lost 76.
The US Navy had 288 and lost 52
The Soviet Navy had 280 and lost110
The Italian Navy had 172 and lost 128
Other Navies such as Netherlands, Poland etc. had small numbers of submarines, but I don't have accurate records of how many.
The total number would be a bit over 2,000
During World War 2, it is reported that over 2,000 variants of Japanese Submarines were used during World War 2. Out of this, it is estimated that 10,000s were likely to be used during WW2.
An estimation of about 600 subs were operated during the war.
Shallow diving submarines are used for reef watching in many parts of the world.
Britain, France, Germany, Italy and USA all used submarines during WW1
ASDIC
Britain, USA, Germany and Italy used submarines during WW1
Yes, many submarines were used in WW1 by most of the major combatants.
During WW2, all the major countries involved used submarines.
Submarines.
World War I submarines were primarily used to locate and attack surface cargo and warships.
See website: Submarine
They're german submarines, used in world war 1 and world war 2