NEW LONDON, Conn. - Floating in the harbor outside the Groton Naval Base is an enormous tube of black steel, so bulky it seems inconceivable it could indeed float. But since 1952, when this tube, equipped with torpedoes and 111 crew and officers, was commissioned as the world's first nuclear-powered submarine, its belly has never touched ground.
These days the USS Nautilus is a museum, a relic of the Cold War and once seemingly permanent records of speed and distance. Its cramped passageways wind like a maze through compartment after compartment furnished with metal piping and metal walls and doors, almost all painted a pale green.
A Navy tour guide stationed in the mess area tells guests marveling at its small girth and four picnic-sized tables that the crew would eat in shifts to accommodate the dozens of sailors. After 89 days at sea, one day short of the Navy's limit, the windowless submarine, so voluminous from the outside, would begin to feel like a milk crate from the inside.
The Nautilus has been retired for almost 20 years, yet still draws people to marvel at its 4,092 tons, down to the wardroom's small luxuries such as the silver serving dishes chosen by then-first lady Mamie Eisenhower. The visitors are a testament to people's fascination with the world lying beneath the oceans' surface - and unease about the dangers there.
Alexander the Great was one of the first known underwater explorers, having ordered his retinue in 332 B.C. to build him a watertight glass barrel and lower him into the sea. He made notes about the animals he saw from, presumably, not too great a depth under water's surface.
The first person to actually build a submarine - technically defined as a watertight compartment that can be propelled through water - was Cornelius Drebbel, in 1624. He packed 12 men into the hull who manned six oars to propel the craft under water.
In the late 1700s, according to historians at the Submarine Force Library and Museum in Groton, an English carpenter named John Day bragged that he could remain submerged for 12 hours. In front of a rowdy crowd off Plymouth, Mass., he and his converted fishing sloop sank underwater. The crowd waited for him to reappear. But Day never surfaced.
An endeavor two years later is credited as the first submarine to engage in battle, using the ocean's darkness as a military asset. American revolutionary David Bushnell, in 1776, built a submersible to attack British naval vessels anchored in New York harbor.
What he created, on display at the submarine museum in Groton, looks like a large wooden keg with a stool inside. But it incorporates a compass, depth gauge, steering mechanism, a variable ballast, watertight hull fittings and an anchor. What Bushnell lacked were a periscope and a way to mechanically propel the keg other than by churning what look like bicycle pedals under his feet.
On Sept. 6, 1776, the night he was to set out to try to attach a small keg of gunpowder to HMS Eagle in the harbor, Bushnell fell ill. His friend Ezra Lee volunteered to take his place. Lee made it to the ship undetected but was unable to attach the keg of gunpowder to the Eagle: As protection against worms, its hull was sheathed in copper.
"It was unsuccessful, but he proved that people could propel themselves underwater," says Lew Nuckols, professor of ocean engineering at the Naval Academy in Annapolis. "It was very crude, but it is analogous to today's Navy Seals. It was the first covert harbor entry."
Until the Civil War, most submersibles were the creations of inventors working alone. The war served as an impetus for more concerted efforts; Confederate soldiers manned small submarines in the waters around North Charleston, S.C., the most notable being the H. L. Hunley - the first submarine to sink an enemy ship.
But the victory was not without a price. For unknown reasons, the Hunley and its nine-member crew never resurfaced. The wreck remained unsighted until 1995, when author Clive Cussler pinpointed its location off North Charleston.
The sub, made from an old boiler, was pulled from the water last summer. In March, archaeologists identified several partial remains and a brass button lodged in 137 years worth of mud and sediment on the sea bottom.
The Navy usually leaves war graves untouched, but Capt. Andy Hall, deputy director of the Navy Historical Center, which is overseeing the project, says the wreck was so close to shore and in such shallow waters that he feared treasure hunters would pillage it.
"It's a highly historical artifact as well," Hall says. "It's important that it be examined. It's an eerie yet respectful feeling of recovering the crew, especially because we have pictures of them standing together before they left."
But the Confederacy's primitive submarines proved generally ineffective in battle, and the Navy showed little interest.