Returning to Scapa Flow, Ross takes on the SMS Karlsruhe, the Kaiser's Imperal warship. Sitting at a depth of 27 metres, this World War 1 wreck is Ross' deepest dive yet. Ross Kemp dives on a series of incredible shipwrecks around the British coastline to reveal some of the nation’s murkiest and best-kept secrets. From the remains of a slave ship discovered off Plymouth, to the Kaiser’s sunken Imperial Fleet in Scapa Flow and an experimental submarine aircraft carrier, which sank with all passengers and crew on deck during its sea trials, Ross uncovers Britain’s hidden maritime past.