As the novel moves towards its close, most readers will feel a grudging respect for officers and crew of the U-boat. But that respect turns to horror in a penultimate scene in which a neutral passenger liner, lights blazing, is torpedoed off the coast of Spain because the U-boat's officers cannot decide whether she is Spanish or an enemy vessel. Luckily the torpedo is a dud and subsequent interrogation of the ship's captain by the Old Man reveals that the liner is indeed Spanish and is en route to South America with over 2,000 passengers. The ship is allowed to sail on, unmolested. But in the novel's most chilling scene, Herr Kaleun tells his officers that had their torpedo not been a dud and had it sunk what turned out to be a neutral ship, they would have had to have destroyed all evidence of their misdeed - and that would include machine gunning to death all survivors. "Only dead men tell no tales," observes the novel's narrator (a young naval war correspondent serving aboard the sub, a role in which Buchheim himself had served during the War).
Das Boot became a bestseller in Germany and was published in the United States two years later under the title The Boat. It was turned into a masterly German television miniseries by Wolfgang Petersen in 1981 and subsequently re-cut into a feature film which was released worldwide in 1981 (see Appendix 4, "Cruel Seas Goes to the Movies" for additional film details).