On a gray February day two years ago, Charles de Gaulle journeyed to Toulon to deliver a speech and attend a memorial Mass honoring 52 naval crewmen who had disappeared along with their ship, the 850-ton submarine Minerve. To the navy's surprise, the President suggested taking a brief dive himself in one of the doomed submarine's sister ships, the Eurydice. The general's ride, to a depth of 130 feet, was a gallant gesture of confidence in the submarines of the Daphné class, to which the Minerve and the Eurydice belonged.
One morning at dawn last week, the Eurydice slipped out of...