Yes, that is a German term. Non-Germans call them submarines.
Subs (Submarines).
The Germans were the first to use Submarines in World War 1. Now i believe that the marines now do at times.
Yes, German submarines were very effective in both world wars. The Germans built excellent submarines and still do.
Mercury used as ballast
the word in German is Unterseeboot -- literally, boat under the sea. The informal name for the vessels are U-Boat.
U boats- for Unterseabooten (under sea boats)
. Submarines
German U-Boats are submarines. In World War 2, the Germans used these submarines to attack in groups of three or more. The Germans called these groups of submarines "wolfpacks". The Americans, British & Canadians also used the name "wolfpack" to refer to a group of German U-Boats.
Submariners.
submarines (U-boats)
Introduced undersea warfare. They were used by the Germans to destroy British ships.