More than sixty British submarines were in commission in August 1914, including newer boats with diesel engines and improved habitability for longer missions. Their crews quickly moved beyond the coastal-defense assumptions under which many boats had been designed, operating in the Dardanelles, Adriatic, and Baltic. The reading credits them with sinking fifty-four enemy warships, including nineteen U-boats, along with 274 transports and supply ships. The results came at extreme cost: dozens of boats and roughly 1,200 sailors were lost, about one third of those who joined the service.
Notable Point · 3:25:35-3:26:52
Royal Navy submariners entered war without a precedent
Britain's young submarine service entered the First World War with little operational precedent, expanded rapidly, achieved substantial results, and suffered the Royal Navy's worst branch-level casualty rate.