Shadows in the Deep — Robert W. MacKay

A thriller set in a Cold War submarine, Terror on the Alert opens in 1962 as the Cuban Missile Crisis is brewing. Naval lieutenant Ted Hawkins rescues a junior officer, but then has to replace the injured man aboard the submarine HMCS Alert. Sent to sea on short notice to contact and shadow Soviet submarines, Ted, hampered by claustrophobia caused by a trauma, must deal with an executive officer who hates him. Tension on board becomes unbearable when they encounter an aggressive Soviet submarine. Explosions, gunfire, and Ted's battle with his nemesis propel the action to a shattering conclusion.