There is a maxim in the cruise-ship industry that the average passenger gains a pound a day while on board. Photograph by Brian Finke

As I left the restaurant, I reflexively patted my pants pockets, checking for my car keys, and tried to recall where I’d parked. Then I remembered: my car was more than a thousand miles away, at an airport lot in Newark, and I was on a cruise ship travelling to Florida from the Bahamas. The ship, Royal Caribbean’s Oasis of the Seas, is so massive that its motion is usually imperceptible to anyone who isn’t looking overboard. Above me on either side blocks of staterooms with inboard-facing balconies rose like apartment buildings, and the walkway I was standing on was flanked by trees and shrubs. Stars were visible overhead, but I couldn’t see water in any direction.

Oasis is the second-largest cruise ship in the world; its sister ship, Allure of the Seas, was built from identical drawings but came out a couple of inches longer. Each ship can carry more than six thousand passengers and twenty-one hundred crew members, and each has approximately the same displacement as the United States Navy’s largest aircraft carriers. Before we sailed, from Fort Lauderdale, I assumed that most of what I’d be eating onboard would have been mass-produced onshore, as is the case with airplane meals, and that food preparation at sea would be heavily microwave-dependent. In the early nineteen-nineties, my wife and I took our two kids on a four-night Caribbean cruise—a trip that, in family lore, is not counted among our spring-break triumphs. We were assigned to a dining table with another family of four, and my main memory of our meals is of the adults making awkward conversation while the children chewed sullenly. The food was mostly stuff that not even a boarding school could get away with now: a sad-looking salad with a single cherry tomato in the center, a fish fillet as rigid as tree bark. Even so, eating and drinking were the main activities onboard. The ship’s amenities included a snack bar at which soft-serve ice cream was available around the clock, and I did not doubt the cruise-industry maxim that the average passenger gains a pound a day.

Since then, America’s global reputation for gluttony has, if anything, increased. At the same time, though, we have become more adventurous and, in many ways, more demanding about what we gorge on. Chefs are the stars of television shows, and the widespread infatuation with locally produced ingredients has been very good for people who grow kale. Dining opportunities on my Oasis cruise reflected contemporary trends. The ship had twenty-three dining venues, among them a sushi-and-ishiyaki restaurant, an Italian trattoria, a restaurant featuring six-course seasonal menus developed by Michael Schwartz, and a cupcake shop. (At most of these, the food was included in the price of passage; a few added a surcharge.) The ship also had twenty galleys, including a butcher shop that supplied all the dining venues, a bakery that never closed, and a prep kitchen near the storage rooms in which workers did nothing but wash, trim, peel, and slice vegetables. Virtually everything I ate had been prepared on the ship, using fresh, unprocessed ingredients. The ship’s cooks even made items that reasonably fancy restaurants buy frozen, such as vegetable and meat stocks, which they reduced in huge tilting receptacles called Bratt pans, and bath-towel-size sheets of dough for apple strudel.

Many of the dishes I tried were ambitious. Chops Grille, the ship’s steak restaurant, featured a seasoned-bacon appetizer—thinner but more irresistibly molten than the similar item at Peter Luger. The tapas sampler at Vintages, a wine bar, included butter-soft piquillo peppers stuffed with cream cheese and feta, and sautéed balsamic-marinated baby onions. The onions had a brownish glaze that made them look like scaled-down Krispy Kreme doughnuts, and they fell apart when I cut them with my fork. Like everyone else, I’d been assigned a table and a dinnertime in the ship’s main dining room, called Opus—which has three levels and accommodates more than twenty-three hundred passengers during each of two evening seatings—but I was free to ignore my reservation. Electronic displays near the ship’s passenger elevators showed how much space was available in each of the dining venues, generated by infrared sensors that monitored the body heat radiated by the people currently eating.

Oasis, like other very large cruise ships, feels less like a nautical object than like a shopping-mall food court with swimming pools on the roof. Yet something about being at sea must weaken the inhibitions that normally prevent people from topping off a huge restaurant meal by sprawling on their bed and calling room service. A person who, on land, can walk past an auction of Thomas Kinkade prints without regret may be helplessly drawn to one in the Boleros Lounge, on Deck 5, across from Starbucks. Maybe oceans exert a powerful transformative force that affects you even when you can’t see or feel or smell the water, and makes you hungry.

The executive chef on my cruise was Lorenzo Dearie. He has a shaved head, penetrating green-gray eyes, and the build and disposition of a rugby player. He was born in northeast England in 1972, began cooking in a pub when he was fifteen, and held a succession of restaurant and hotel jobs in London, Scotland, Bermuda, the Cayman Islands, Canada, and New Zealand, where he has lived since the late nineteen-nineties. He went to work at Royal Caribbean seven years ago. “To have three hundred and fifty people working for you is a lot of fun,” he told me. We met in the Café Promenade, on Deck 5, and to get from there to the ship’s service area we first had to cross a pedestrian plaza, which was crowded with tortoise-paced, plus-sized people carrying cocktails and beers. “I can’t walk slow,” he said, when we became stalled, momentarily, behind a wandering bride and her attendants. (Oasis averages two or three weddings per cruise.) Dearie moved through the crowd awkwardly, like a child learning to ice skate. “This is killing me,” he said. “I’ve got twenty outlets to check, and I check them three, four times a day. I usually run.”

We moved faster once we’d reached I-95, a two-lane employees-only corridor that runs most of the length of the ship, on Deck 2. From there we climbed a service stairway and crossed a corridor to the ship’s largest galley, which serves Opus. Everything in it was sized for giants: ovens, soup kettles, an automated pot washer large enough to wash a washing machine. Dearie’s staff was preparing for the first dinner seating. A long stainless-steel serving counter had been divided into sections for the evening’s ten entrées, each of which was marked by a labelled photograph: pork, grilled salmon, beef sliders, lobster. (Oasis passengers eat a metric ton of lobster during a typical seven-day cruise.) The Opus kitchen has one executive chef, five executive sous-chefs, eleven sous-chefs, fifty-five chefs de partie, four demi-chefs de partie, and a hundred and sixty-eight commis, or range chefs. Members of various ranks are distinguishable by their uniforms, including neckerchiefs in different colors.

“The desserts are over there,” Dearie said. “You see the tiramisu? Opus will go through at least forty trays tonight, on the three decks.” For the past few weeks, he said, one of the ship’s restaurants had been serving a new item, devised by a colleague: cheesecake lollipops, baked fresh each day. Later, in the ship’s pastry galley, I watched a cook popping new ones from a molded silicone baking sheet and arranging them on a tray. They were shaped like miniature pies, and had been made from scratch, including their graham-cracker crusts. Dearie said, “When we first rolled them out, we had sixteen or seventeen hundred kids on board, and we were going through fifteen or sixteen hundred of just this one item every single day.”