There are different answers to that but the most common one is that the USN had 288 submarines in WW2
326
2,200,000 Soldiers 97 Warships 40 Submarines.
Why don't you just Google "World War 1 Submarines?"
1, 200,000 Soldiers 30 Warships 11 Submarines.
The British lost 76 submarines during WWII.
Yes, many submarines were used in WW1 by most of the major combatants.
52
eighty five
759
9
World War I submarines were primarily used to locate and attack surface cargo and warships.
USN about 250.