At 12:45 on a Wednesday, the formal dining room at Aquagrill is crazy busy, with nearly every seat occupied by a business lunch crowd. No surprise, since the 2011 edition of Zagat rated the place the best raw bar in New York. Luckily, we’ve thought to make a reservation.

Our server suggests the fluke roll and the Maine crevettes appetizers — the daily specials — and they are certainly tasty. But we’re really here for the oysters.

New York City, after all, is historically tied to the oyster. Some of its streets are even paved in oyster shells. Like Pearl Street, way downtown in the financial district, where the shells that washed up from the East River were ground into the sidewalks.

So bountiful was the oyster supply in New York Harbor during the late 19th century that the city was the world’s largest source of the succulent bivalves. Not only were oysters an affordable food for the working classes, but they also created jobs and prompted the growth of the New York restaurant industry.

By the early 20th century, the oyster beds in New York Harbor had been exhausted, but the taste for oysters didn’t die. Although their offerings are no longer harvested from the East River, oyster bars retain a cultlike following in the Big Apple. Beyond the city’s dozens of raw bars, the craze for oysters has extended to many places that wouldn’t normally have them on the menu.

Like New Yorkers, we Marylanders love our oysters. So four friends and I have hopped the train from Baltimore, setting out to tackle as many New York oyster bars as we can in a day.

Aquagrill, in SoHo, is our first stop. The day’s oyster list consists of 26 varieties from the East and West coasts, Alaska and British Columbia, ranging in price from $2.05 apiece for a Connecticut Blue Point to $4.15 for an Alaskan Canoe Lagoon. The Oyster Sampler provides one of each oyster on the list for $73.65. I upgrade the $23 Shucker’s Special (a half-dozen featured oysters with a bowl of soup or chowder and a mesclun salad) to include a pair of Wellfleet (Massachusetts) and Canoe Lagoon, which the server recommends because they’ll soon be out of season. My buddies order up about three dozen more oysters, and we wash everything down, appropriately, with pints of the Long Island brew Blue Point Toasted Lager.

At the end of the meal, we tell our server that we’ll be hitting other oyster bars in the city.

“Too bad you came here first,” she says. “We’re the best. We’re the only place that doesn’t pre-shuck anything.”

She may have been right. I’m not sure whether the oysters at any of our other destinations are pre-shucked, but the lunch at Aquagrill will be tough to beat. Not only are the oysters fresh as could be, but the dining room is clean and comfortable and the service impeccable.

Our next destination is Fish, in the West Village, which also provides the opportunity for a pit stop at the Blind Tiger Ale House just across the street, where we drink some beers by the fireplace while we wait for our appetites to return. Where Aquagrill is casual but upscale, Fish is more of an Old World tavern and a little easier on the wallet. The Famous Raw Bar Special includes six Blue Point oysters or six clams on the half-shell with house wine or P.B.R. (Pabst Blue Ribbon) beer for $8.