The reason of using submarines during World War I was to stop the Central Powers at the sea itself. The Allied Forces which had larger fleet of submarines surrounded the position of Central Powers, and the Central Powers retaliated, not only to break the blockade but to establish a blockade of their own submarines and raiders for the United Kingdom and France.
The United Kingdom was a dominant power in naval warfare in the nineteenth century and the only nation that could stand to some extent in front of the power of UK was Germany. All other nations had a few battleships and larger proportions they had were submarines or destroyers.
Although submarines during those times didn't have the ability to stay submerged for long, they were used quite frequently while attacking merchant ships which were poorly defended.
The United Kingdom was a dominant power in naval warfare in the nineteenth century and the only nation that could stand to some extent in front of the power of UK was Germany. All other nations had a few battleships and larger proportions they had were submarines or destroyers.
Although submarines during those times didn't have the ability to stay submerged for long, they were used quite frequently while attacking merchant ships which were poorly defended.
