The British Royal Navy was having a hell of a time with the onset of the war. Not only had the Empire of Japan attacked their colonies in the East almost immediately after declaring their entry into the conflict, forcing the British to divert their maritime forces to deal with this new threat.
Nearly a month had passed since the Great War began, and Britain had already lost over a dozen transport ships in their attempts to cross the North Sea. Any attempt to ferry troops across the English Channel was met with critical failure.
Attacks occurred time and time again without warning, resulting in devastating losses as the British scratched their heads, trying to figure out just what the hell was sinking them. Their confusion was understandable.