Answer:
Step-by-step explanation:
German submarines made unrestricted attacks on ships.
German submarines were on a mission to destroy merchant vessels carrying supplies to allied forces in order to hinder their war efforts. Aided by intelligence reports on the location, destination, and speed of merchant vessels, the U-boats would search the seas for victims. The damage inflicted by U-boats during World War I was powerful. Their ability to submerge and to surprise enemies led to massive casualties: Germany and Austria-Hungary sank almost 5,000 merchant ships during World War I, killing approximately 15,000 Allied sailors.