You could learn about the S.S. Eastland tragedy, the largest single loss of life in Chicago history, from a book or a nautical-accident journal (there's gotta be one, right?). Or you could board a tour boat in downtown Chicago and catch the story as it crackles over the PA system, if you're dutifully attentive and not trying to wiggle away from the soda your seatmate just spilled.

But for a more engaging lesson on the Eastland, pull a kayak right up to the spot of the accident, grab hold of the riverside bulkhead and listen, as I did during a paddling tour of the City of Broad Shoulders. "She was loaded to near capacity and people just kept boarding," says David Plascencia, a ponytailed part-time actor who is guiding five of us, in kayaks, down the Chicago River on a sunny June day. The two-hour paddle, with an outfit called Wateriders, is billed as an architectural and ghosts and gangsters tour. I get an eerie sense we're headed into the "ghosts" segment.

On July 24, 1915, the Eastland was preparing to shuttle 2,572 Western Electric employees onto Lake Michigan for a company cruise. Leaving its Chicago River port, the ship was already top-heavy -- the captain had dumped some ballast to raise the rails farther above the waterline -- and when the growing crowd packed onto the river side of the vessel, the Eastland listed to port.

"People rushed to the other side and she tilted back, and then they ran back," says Plascencia. The Eastland eventually rolled into the river, taking 844 people to their deaths in 20 feet of water. "A lot of employees of these buildings around here" -- we are just upstream of the Clark Street bridge -- "say their offices are haunted by Eastland ghosts," he says. "Oprah's got a production studio nearby. I hear she won't stay there alone after dark because of the ghosts."

A dubious claim, but the kayaking has me in an agreeable mood, so I let it slide. We knife back across the river, with Chicago's crisp and colorful skyline surrounding us: the beaux-arts facade and French Renaissance detail of the Wrigley Building; the hulking 1931 Merchandise Mart, the world's largest commercial building; the soaring Chicago Tribune edifice (another Gothic wonder); the funky corncob cylinders of Marina City, which architect Bertrand Goldberg designed after a feud with his mentor, Ludwig Mies van der Rohe, who drew up the clean and geometrically pure One IBM Plaza.

And of course the Shaquille O'Neal of Chicago construction, the Sears Tower, which was the world's tallest building from its completion in 1974 until 1997, when it was eclipsed by the twin Petronas Towers in Kuala Lumpur, Malaysia. The Sears Tower "is really nine skyscrapers bundled into one," Plascencia says, explaining that the building is able to stand so tall (1,450 feet) because it comprises a cluster of huge steel tubes bound together, like pencils in a rubber band.

This was among the many details Plascencia dispensed that I didn't recall from the motorized, cattle-boat architectural tour I took during a Chicago visit last year. The interaction of being right down on the river (vs. above it), coupled with the physical thrill of paddling and the intimacy of a small group, made the tour much more vivid and memorable than on a larger vessel.

That, and the competition kept us on our toes. "Going a little fast there, aren't you?" Plascencia yells to a passing tour boat as foot-high waves advance on us from its wake. The pilot, unable to hear over his own motor, smiles and waves. More than one boat will exceed the 4 mph no-wake speed limit on the river but, despite the tippy sensation of paddling through wake waves, Plascencia tells me he's had only one client fall in the river -- a guy who insisted on taking a kayak without foot pegs, which are key to stabilizing it.

If the afternoon held only one certainty, it was that I would keep my body out of the notoriously foul water at all costs. The tour had started behind a sleek new office complex north of the city, where the water was the hue of strong coffee and the dock offered a view of a rusty bulkhead and a Greyhound bus depot across the river.

Surprisingly, fish live here -- mainly carp and goldfish, with dozens of other species sparsely represented -- but the only one we see (a two-foot carp) is belly-up. (And, in fairness, I must mention that the Main Branch of the river, which flows in from Lake Michigan, is far cleaner than the North and South branches. At one point on the Main Branch, we can actually see the river bottom about six feet under, which Plascencia says is a first for him.)

We float under the Washington Street bridge and cluster our boats together -- Plascencia calls this "rafting up" -- opposite a massive cement wall of the Civic Opera Building. A two-foot hole in the bulkhead disappears ominously into the city's bowels, feeding Plascencia a convenient segue into some gangster history.

In 1856, Chicago launched a project to protect the burgeoning downtown from frequent flooding (Lake Michigan had an annoying habit of spilling onto city streets during storms). Officials ordered many streets and buildings raised, some by up to 12 feet. The resulting warren of passageways and earthen rooms under the newly elevated city gave mobsters, drunks, hookers and gamblers a place to ply their trades -- and spawned the term "underworld."

Leading this seedy pack in the 1860s was Roger Plant, a diminutive gangster who ran a "vice resort" at the corner of Wells and Monroe streets that was known to police as the Barracks, but dubbed Under the Willow by Plant for a lone tree nearby. Plant stood 5 feet 1, weighed about 130 pounds and, Plascencia tells us, was feared by almost everyone in Chicago. "The only person who wasn't afraid of him was Mrs. Plant. She weighed about 300 pounds and, when they argued, she'd lift him by his collar with one hand and slap him with the other until he cried like a baby."

Lest we view Plant as an anomaly, Plascencia recounts the sordid tale of Mickey Finn, who owned the Lone Star Saloon and Palm Garden restaurant on South State Street. "He concocted a knockout drink that never failed and had all his bar girls slip it to unsuspecting strangers," Plascencia says. (You know where this is going, right?) "They woke up the next day in the alley behind the bar, naked and broke." The cops closed the saloon in 1903 -- the Chicago Public Library now stands on the site -- but, of course, the phrase survives.

As we mosey back upstream, passing Wolf Point, where the three branches of the Chicago River meet, we are met by Wateriders owner Charlie Portis, who pulls a small travel guitar out of his kayak. We raft up as he sings a tribute to Chicago to the melody of Bob Dylan's "Blowin' in the Wind."

Portis can barely carry a tune, but his lyrics are endearing:

How many buildings has the world put up

Reaching ever nearer the sky?

And how many stand as Chicago did it first,

Steel frames soaring to fly . . .

As tour epilogues go, this beats the heck out of "Please, watch your step as you disembark the boat."

Wateriders (312-953-9287, www.wateriders.com) offers kayak tours of Chicago generally at 10 a.m., 2:30 p.m. and 5:30 p.m. Saturdays and Sundays through autumn (weather permitting); call for exact times. Private groups of six to 20 people can arrange tours seven days a week. Reservations required for all outings. Tours run about three hours and depart from 900 N. Kingsbury Ave., just north of Chicago Avenue in the Domain building. Wateriders provides all equipment and drinking water. Price is $55 per person, $50 per person for groups of four or more.

John Briley last wrote for Travel about vacationing cheaply in Big Sur, Calif.

Visitors paddle up to the Merchandise Mart during a kayak tour of Chicago.Paddlers float by the Boeing Building and clock tower during a kayak tour of Chicago's history and architecture.