Strange Metal Fish : HITLER’S U-BOAT WAR: The Hunted, 1942-1945; By Clay Blair; Random House; 864 pp., $45 : BLACK MAY; By Michael Gannon; HarperCollins; 492 pp., $30 : BLIND MAN’S BLUFF; by Sherry Sontag and Christopher Drew; PublicAffairs; 352 pp., $25

Generations of teachers have lured students into Jules Verne’s “20,000 Leagues Under the Sea” by marveling at how a Frenchman in 1870 could have envisioned the technological wonder that is the modern submarine. Almost a century later, the U.S. Navy paid homage to Verne by giving its first nuclear-powered submarine the same name as the undersea raider commanded by the mysterious Capt. Nemo: Nautilus.

Surely there can be no harm if this educational ruse leads students to one of the world’s great page-turners, a novel that Ray Bradbury in his enthusiasm ranks with “Moby Dick.”

But the truth is that, long before Verne, men had been interested in building what Bradbury calls “strange metal fish” to glide unseen beneath the water and strike deadly blows upon their enemies. The quest for the ultimate dreadnought led to dreams of building a ship that would deliberately sink itself.

Alexander the Great in 332 BC went underwater in a glass contraption, and Leonardo da Vinci was said to have developed an ur-submarine but then had moral qualms--not shared later by Nemo or German U-boat Wolfpacks or U.S. submarine captains in the Pacific during World War II--about “the evil nature of men who practice assassination at the bottom of the sea.”

Crude submarines played roles in both the Revolutionary War and Civil War. Then, as now, a submarine is a good equalizer, allowing a lesser power to strike a strategic and demoralizing blow at a greater power. Not for nothing are submarines a much-desired commodity in the post-Cold War era among nations looking to beef up their military reputations without the expense of buying or building more expensive hardwares such as planes and aircraft carriers.

A staple among post-Cold War potboiler fiction--notably Patrick Robinson’s “Nimitz Class”--is that a rogue nation will beg, borrow or steal a Russian-built sub to strike a psychologically devastating blow at the U.S. Navy on the high seas.

As for Nautilus, that was the name given to a prototype developed by American inventor Robert Fulton in his failed attempt in 1796 to interest the French in using his invention to achieve parity with the much larger British Navy. The French, it can be said, truly missed the boat.

Drew Middleton, in his classic 1976 study, “Submarine: The Ultimate Naval Weapon--Its Past, Present and Future,” concluded of the role played by the submarine in both world wars in the 20th century: “It is apparent that the submarine has had a greater impact on the troubled history of this century than any other weapon.”

To write about submarines--the first extended treatment is thought to be a book by English inventor William Bourne in the 1580s--is to inevitably confront the morality of submarine warfare, the hardships--often horrors--of men in claustrophobic confinement and dire circumstances and the special camaraderie shared by such men.

“Carriers are showboats for admirals,” a former submariner once told me. “A submarine is for men who want to be part of the fight and are willing to put up with conditions that most would find intolerable.”

A submarine, by its nature, is an offensive weapon designed to go into harm’s way. Every sailor knows his life is expendable in pursuit of the mission. At the outbreak of World War II, Germany had the finest submarines and submarine sailors in the world, but by war’s end the Germans had lost 75% of their 859 U-boats, a third of them on their first mission.

Journals kept by submariners of various nations, in both wars, talk of stifling heat, brutal cold, fetid air, damp clothes, clouds of brain-numbing diesel fumes, battery explosions and toilets left for weeks to overflow (lest a flushing alert the enemy). Oxygen was so depleted that a match would not stay aflame. British sailors were issued buckets for their vomit, which they kept at their battle stations.

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In the superb “Book of Submarines: A Political, Social, and Military History,” published in 1997 by Navy Times, a Gannett publication, author Brayton Harris quotes a British radioman from World War I: “There was no bath and only one lavatory for the use of all three officers and 29 men aboard. Few shaved and no one changed their clothes from the beginning to the end of the voyage. The officers used eau-de-cologne to mask their body odour and the indescribable damp, oil-laden, stale smells of the sweating interior of the boat.”

The death most feared by a submariner is the slow oxygen deprivation of being trapped on the bottom, unable to rise and able only to await the inevitable. In the late 1930s, a U.S. Navy officer, under the pen name Alec Hudson, published a series of submarine short stories in mass-circulation magazines, including one story entitled “Battle Stations!” in which a sub is crippled by enemy depth charges and driven to the bottom of the sea, too deep to attempt escape: “Entombed in our prison of steel, we patiently waited. Waited for death to arrive and release us. . . . Into our bones crept the chill of the ocean, the numb, lifeless cold of the depths of the sea. . . . In time, in spite of our chemicals (kept aboard to replenish oxygen), the carbon dioxide percentage would creep up so high that it would be suicide to attempt to use the [escape] lung. Nothing would then remain but lingering death.”

Though none of the recent efforts has reached the celebrity of That Book by Tom Clancy, these are boon times for submarine books of all stripes: fiction, biography, history and investigative journalism. Patrick Robinson, a Fleet Street journalist who covered the 1982 Falklands War, in which an undetected British submarine sank the Argentine cruiser General Belgrano, shows no sign of slowing. Edward L. Beach, a retired submariner whose 1955 novel “Run Silent, Run Deep” was seized upon by Hollywood, has just given us his memoirs, “Salt and Steel: Reflections of a Submariner.”

Clay Blair’s “Hitler’s U-Boat War: The Hunted, 1942-1944” is a continuation of Blair’s much-praised World War II history, including a history of the U.S. submarine service. As always with Blair, the work is meticulously reported and smoothly written.

If ever it was doubted that submariners of all nations share a unique bond, Blair’s description of the Nuremberg trial of Adm. Karl Donitz, mastermind of the U-boat war, is instructive. Donitz was convicted of war crimes, particularly for ordering his boats not to rescue survivors, and sentenced to life in prison (he was released after a decade, at age 80).

Hundreds of Allied naval officers protested Donitz’s conviction as unfair and bred from a basic misunderstanding by the civilian judges of the ferocity of submarine warfare and the tacit understanding by all submariners that they will not enjoy the kind of civilities extended to those wounded or stranded during land battles. Just a generation before, there had been a viewpoint among many submariners that they had an obligation to surface before attacking and then to rescue survivors: That idea of gentility was a quick casualty of war.

“In their desire to avenge Pearl Harbor,” writes Blair, himself a World War II submariner, “American submariners shot at and sank Japanese merchant ships without warning, rarely attempted to assist survivors, and, on a few occasions, murdered Japanese survivors in lifeboats or the water.”

Michael Gannon’s “Black May” is the story of how the Allies broke the back of the U-boat offensive in May 1943. The writing is often thick, but Gannon, an emeritus professor of history at the University of Florida, has unearthed some gems, including transcripts of the conversations of German submariners held as POWs by the British, who bugged their barracks. One German submariner was heard telling his countrymen, “Our morale was about as good as if we were being led to the slaughterhouse.” To which one replied, “That was some boat! It was bound to sink! We all said that the first day.” Armed with such candor, Winston Churchill knew that talk of the indomitable German submarine force was only propaganda.

Only now that the Berlin Wall has crumbled is the American public learning about the almost daily confrontations during the Cold War between U.S. and Soviet submarines. Each side shadowed the other, both sought to electronically steal secrets, both were ready to strike with nuclear weapons.

In their best-selling book “Blind Man’s Bluff,” journalists Sherry Sontag and Christopher Drew chronicle the undersea hide-and-seek campaign between the two superpowers; the title comes from a children’s game in which the player cannot see his opponent. At one point, the United States successfully bugged undersea cables used by the Soviet Navy as communication links with their far-flung submarine bases.

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Whether such derring-do kept the world from war by providing the United States with inside information about Russian intentions and capabilities or whether it brought us all closer to the brink by risking discovery and armed conflict is one of the moral quandaries the book explores.

It is not a new debate. Verne’s Capt. Nemo thought his actions the quintessence of morality and believed his submarine would rid the world of war by destroying all those with the ability to wage it. Whether Nemo is a madman or moralist is at the center of that troubling novel. “Nemo’s ship pursues men to remind them of their wickedness, to improve it, or be sunk,” Bradbury has written.

The U.S. Navy has kept a chilly distance from “Blind Man’s Bluff,” issuing a no-comment about its revelations concerning the loss of the Scorpion in 1968, the collision between the Tautog and a Soviet sub in 1970 and the half-billion-dollar CIA boondoggle to steal a sunken Soviet sub with the Glomar Explorer, a salvage ship built by Howard Hughes. The service also has reminded sailors to keep their lips zipped: “There is no change in existing policies prohibiting the release of classified information. . . .”

Sontag, a former reporter for the National Law Journal, and Drew, special projects editor for the New York Times, purposely left out certain information that might have compromised current operations. To keep track of a reduced number of “Ivans” and a growing number of Third World submarines, U.S. boats are still on the prowl.

Even in the context of the Cold War, the submarine service was unique: “The men who serviced those cables at the bottom of the Barents and Okhotsk [seas] knew they faced immense risk. The self-destruct charges they carried were a grim reminder.”

The Cold War secrecy, though taken perhaps to extremes, was nothing new to the submarine service, whose nickname “the silent service” bore a double meaning. Ever has it been for submariners of all nations. As Rudyard Kipling wrote in “The Trade”:

Their fears, their fortunes and their fames

Are hidden from their nearest kin;

No eager public backs or blames,

No journal prints the yarn they spin

(The Censor would not let it in!)

When they return from run or raid.

Unheard they work, unseen they win.

That is the custom of The Trade.