The steady transformation of New York’s waterfront from wasteland to playground means more of us are spending time along the city’s edge. That can lead a person to wonder: What, exactly, is down there? Until recently, we had patchy knowledge of what lies beneath the surface of one of the world’s busiest harbors. What we did know came largely from random anecdotes, and depth soundings done the way Henry Hudson did them—by rope and lead sinker. This first GPS-era picture comes from the team at Columbia University’s Lamont-Doherty Earth Observatory, who have methodically swept the lower Hudson with state-of-the-art sonar. LDEO’s Dr. Frank Nitsche stitched together their data, along with several other researchers’ work, into this elegant color-keyed map, which we’ve supplemented by talking with sea captains, historians, and the divers pictured above. There’s a whole other city down there. Here and on the following pages is your guide.
1. A New Main Stream
The Hudson’s main current has, for all of recorded history, clung to lower Manhattan’s edge, skimming along the West Side. Battery Park City, built in the seventies, juts out into that flow, and since then, the current has been cutting a new channel, out toward the center of the river. That current is scraping mud off the top of the Lincoln Tunnel where it never did before; the underwater traffic tubes have lost 25 percent of their soil coverage in some spots. If the tubes ever became exposed, they would be at risk for shifting, cracking, and terrorist threats. The Port Authority is studying solutions.
2. Teredos and Gribbles
Two kinds of hungry pests gnaw away at the pilings that hold up structures like the FDR Drive, the U.N. school on East 25th Street, and the Con Ed plant at 14th. Teredos, which start life looking like tiny clams, grow up to be worms “as big around as your thumb, and nearly four feet long, with little triangular teeth,” says commercial diver Lenny Speregen. Like underwater termites, they devour wood. And Limnoria tripunctata, a.k.a. “gribbles,” are bugs about the size of a pencil dot that look like tiny armadillos, and eat not only wood but also concrete. Speregen says he’s seen fifteen-inch-diameter columns that have been gnawed down, hourglass style, to three inches. The city has tried jacketing pilings in heavy plastic to keep the critters out, but it hasn’t worked well: Floating ice tears up the jackets in winter. “I never said this wasn’t a war,” says Speregen.
3. A 10,500-Mile Gas Main
That groove on the riverbed is a pair of 24-inch gas mains, laid down in the fifties, that—believe it or not—constitute the business end of a network of pipes that runs all the way from the Gulf of Mexico. (Gas takes roughly a week to make the trip.) This pipeline and another at 134th Street supplied 367 billion cubic feet of gas last year—about half of what we used. Since 9/11, the points where it comes ashore have been patrolled daily.
4. A Pair of Piggybacked Shipwrecks
The LDEO researchers know of at least 300 wrecks in the lower Hudson below Troy, but they won’t tell you where most of them are. “They’re archaeological sites,” says William Ryan, one of the group’s senior scientists, and the state (which funds his research) has concerns about amateur treasure-hunters who can’t handle the currents. One notable wreck, which Ryan will place only “near Yonkers,” includes not one ship but two: A cabin cruiser sits atop the flattened remains of a much older vessel, probably a nineteenth-century sailing ship.
5. A Freight Train
It was carrying passenger baggage one afternoon in 1865, and failed to stop at the Peekskill drawbridge, which was open. Two men were killed.
6. Dead Bodies
When homicides and suicides end up in the river during winter, they often stay underwater until April, when decomposition speeds up, bloating them with gases. They then bob up, and currents have been known to drive them to nooks near the Seaport and Manhattan Bridge. “The worst one I ever saw was half in the mud, half out,” says John Drzal, a veteran of the NYPD scuba team. “The skin was peeling back.” He scuttles his fingers up his arm. “The critters were eating it.”
7. Surveillance Systems
The U.S. Coast Guard operates anti-swimmer sonar systems, which are moved around as they’re needed in the harbor. The gear pings signals out, and displays hits—indicating unidentified people or boats—on a video screen. The Coast Guard also does pier sweeps: “If someone puts something on a piling”—say, an electronic device—“we find it,” says USCG gunner’s mate Dave Boles. In 2007, near Liberty Island, he recalls, “someone was spotted in a black Zodiac at night, and we had to check it out.” The mystery boater was never identified.
8. State Secrets
A couple of years ago, “at Kings Point Maritime Academy,” says Boles, “someone dropped a coding device, a piece of secret equipment, and we had to recover it.” (Yes, the guy who dropped it was on our side, and yes, they got it back.)
9. Stripped Cars
In the bad old high-crime days, a virtual fleet of auto carcasses ended up in the East River, near the Brooklyn and Manhattan Bridges. One police diver has said that he would tell his partner, “Go to the Chevy, make a left, and if you come to the Dodge you’ve gone too far.” Most were carted away during a cleanup in the eighties, but a number are still down there. Speregen says that the last time he dived nearby, “to be honest, I thought I saw a cement mixer.”
10. Rebar, and a Lot of It
As the coastal beaches and mud flats became docks and roads, the water’s edge has been sharply defined with concrete. Where it cracks, the coast bristles with rusting steel reinforcement bars. Harbor divers have to watch themselves to avoid getting snagged or injured. Random junk tends to collect in and around it: old tires, garbage cans, busted-up bicycles.
11. A Formica Dinette
“In the East River, at about 16th Street, there’s one of those old dining-room tables, the kind with a Formica top and the grooved metal bands around the edge,” says Speregen. “It’s standing upright, totally free and clear. It makes me want to go down there with teacups and set it up.”
12. Another Shipwreck
Unidentified, at 37 feet.
13. Hudson River Alligators
The quaint wooden pilings you see at the edge of Manhattan, the ones that trace the outlines of long-gone piers, are a hazard in the making. When a storm knocks one of them loose, the resultant floater—a “Hudson River alligator”—becomes a twenty-foot battering ram. Army Corps of Engineers patrols scoop them up, but they can’t spot every one. “You’ve seen a SeaStreak, those fast commuter ferries that serve Wall Street?” says Speregen. “One’s gonna get impaled one of these days.”