"A Sub and a Submarine: The Story of H.M. Submarine R19 in the Great War" by Percy F. Westerman is a gripping account of naval warfare during World War I. Westerman's narrative takes readers beneath the waves into the world of submarines and their crucial role in the war effort. With vivid descriptions and a keen understanding of naval tactics, this book immerses readers in the challenges and bravery of submarine crews. It's a must-read for history enthusiasts and those fascinated by the undersea battles of the Great War.