The Gatecrashers (Nicholas Everard Series)

Nick Everard and his son Paul return in this final chapter of the Everard saga. Paul commands a state-of-the-art midget submarine, sent to sneak up on the formidable German battleship Tirpitz and lay explosive charges. It's one step away from a suicide mission, but Paul must try-for if he fails, his father Nick's escort of an Arctic convoy hardly stands a chance.