Percy F. Westerman 
Rival Submarines [PDF ebook] 

Renowned action-adventure author Percy F. Westerman gained his knowledge of nautical warfare the hard way — through two stints of service in the Royal Navy. He later turned his experience on the high seas into a series of gripping thrillers that has captivated generations of readers young and old alike. The Rival Submarines is full of the kind of edge-of-your-seat excitement that propelled Westerman to the top of the bestseller list in his era.