British sub war — WWII
These aren’t actually “four utterly gripping naval adventures”, but rather one 1200 page novel following two Royal Navy submarine officers over the six years Britain fought Germany, Italy, and Japan during the Second World War.
Ranging from the Arctic Ocean to the Mediterranean to the South Pacific, the engagements fought both against the enemy and the weather, as well as against their own nerves after too many close calls, are gripping; their relationships with their fellow officers, their men, and with women that they meet and come to love as important as the battle scenes.
Not all of the book is completely realistic. The treatment provided to Lieutenant Peter Harding for what was then called combat stress and we now call post-traumatic stress disorder would not have happened in the 1940s (nor any time since). As a former (US) Navy Subject Matter Expert in combat stress, I know better. I rather wish that the author hadn’t gone there.
Still, this very long novel (divided into its four parts) is worth reading.
Recommended.